body1
stringlengths 20
4.1k
| body2
stringlengths 23
4.09k
|
|---|---|
Possible Duplicate: Is there any reason why I should use equation when I align seems to produce the same output? The reason I am asking is that I like solving math using LaTeX. Sometimes I write a single equation using the equation environment, but later realise I need to include more equations aligned to the first in that same environment. Then I need to change the \begin{equation} \end{equation} to \begin{align} \end{align} and include the &s as appropriate. I am thinking then: why not always use align, maybe even including the & before the equal sign, just in case I need to include more stuff there later? If they behave the same, and one is more flexible, why use the other at all? Or are there differences and reasons why I should avoid using align when there is a single equation? | I always use align in my documents, and avoid equation. Is there anything wrong with that? My reasoning behind this: align > equation, so why not use it? |
What is the default password of the sudo? I visit some forums, it tells that the default password is password, but it doesn't work, how can I determine the password? | I'm working on a Ubuntu system, and my client has completely forgotten his administrative password. He doesn't even remember entering one; however it is there. I've tried the suggestions on the website, and I have been unsuccessful in deleting the password so that I can download applets required for running some files. Is there a solution? |
How happy Harry was having seen Toby's house! I don't know whether this sentence is grammatically correct or not! In my opinion, the part "having seen Toby's house" is used as a supporting idea, which is similar to this: "Keeping these ideas in mind, we compiled this book for young readers." Please help me! My question is a different problem, I just don't understand the role of "having seen Toby's house"part, and wonder if it's okay to combine with "how happy harry was". | I am a chinese student and one of my friend, a chinese, wrote sentences like this: Just a little above me, he was fighting with all his might. On the summit of the mountain, he cried with joy. He was pretty certain that these sentences were correct but I am not so sure. I've heard sentences like His eyes bright, he talked vigorously or Her coat barely on her shoulder, she dashed out of her house, but I have never seen sentences like the ones my friend wrote, the ones with no subject in the front. Can anyone tell me the name of the sentences my friend wrote? And if possible, can you also tell me if the name of the sentences I wrote is verbless clause? Thanks. |
I see that df reports a 100% disk usage for a file system. How can I see which folder is eating the disk space? [root@rocks7 mahmood]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/rocks_rocks7-root 50G 48G 0 100% / devtmpfs 32G 0 32G 0% /dev tmpfs 32G 0 32G 0% /dev/shm tmpfs 32G 9.3M 32G 1% /run tmpfs 32G 0 32G 0% /sys/fs/cgroup tmpfs 16G 32M 16G 1% /var/lib/ganglia/rrds /dev/sda1 976M 709M 201M 78% /boot tmpfs 6.3G 12K 6.3G 1% /run/user/42 tmpfs 6.3G 0 6.3G 0% /run/user/1000 | What explains the discrepancy in usage (82 GB vs 13 GB) that I see below? Using df: $ df -h / Filesystem Size Used Avail Use% Mounted on /dev/sda2 96G 82G 9.9G 90% / Using du: $ sudo du -cshx / 13G / 13G total |
I want to unallocate a partition so that I can merge it with another partition using GParted. How can I achieve this? | Previously, I have installed Windows 7 on my 320 GB laptop with three partitions 173, 84 and 63 GB each. The 63 GB partition was where the Windows was installed. The rest were for file containers. Now I changed my OS to Ubuntu 12.04 LTS. I installed Ubuntu by replacing the entire Windows 7 on the 63 GB partition. The rest of the partitions remain as an NTFS Windows partition and I can still access them both (the 173 and 84 GB partitions). Now I want to change the two partitions of Windows into an Ubuntu format partitions plus most importantly, I want to extend the 63 GB partition to more than a 100 GB because at the moment I am running out of disk space. Whenever I try to install any application, especially using wine, it always complains for a shortage of disk space. How do I do the extending activity before I entirely format my laptop again and lose all the important files on my partitions? |
When should we be using "to me", and for what occasions are "for me" better? Take for instance the following sentence: "It's a no-brainer to/for me that schools should be subsidized by the government." | Prepositions are tricky to figure out. I'd like to know whether or not I can use these two prepositions interchangeably in the following examples. It's very important for me/to me to study abroad. For me/to me all that matters is how much it will cost. You are the most beautiful girl, at least for me/to me. Living in our house is just unbearable for me/to me. As an ELL, I have to make sentences in a way like assemblying parts. At times, the contrived sentences may seem to be a little bit unnatural to native speakers, so the examples above are just tokens here. There must be better ways to convey the meaning. |
How do you prove that path of a satellite or a planet is a second degree curve? In other words, how do you prove Kepler's law which states that planets move in elliptical paths? | How can analytically be the ? I found some extremely synthetic equations which from the (in particular $\mathbf{F} = m \mathbf{a}$) tried to obtain the Kepler's laws, but even if it seemed to be a nice procedure they were too much incomplete. |
Let $F$ be an algebraically closed (hence infinite) field and $n$ a positive integer. For a subset $S$ of $F^n$, let us use the following notation: $J(S):=\{f \in F[x_1,...,x_n] : f(a_1,...,a_n)=0$ for all $(a_1,...,a_n) \in S \}$ There is a theorem in Hungerford's Algebra, Section VIII.7, which asserts $J(F^n)=\emptyset$, with proof omitted. Is this an typo? I think, at least, the zero polynomial $0$ belongs to $J(F^n)$. On the other hand, how do I have to prove the inclusion $J(F^n) \subset 0$? It seems obvious, but I cannot write down rigorously. | I am working on a problem from Ideas, Varieties, and Algorithms: Show that if $f \in \mathbb{C} \left[x_1, \dots, x_n \right]$ vanishes at every point of $\mathbb{Z}^n$, then $f$ is the zero polynomial. My attempt so far: This proof is by induction on $n$. Let $f \in \mathbb{C}\left[x\right]$ vanish at every point in $\mathbb{Z}$. Then, it must be identically the zero polynomial, as a polynomial of degree $d$ has at most $d$ roots. Hence, $f$ vanishes at every point at $\mathbb{C}$. Now, assume that $g \in \mathbb{C} \left[x_1, \dots, x_{n-1} \right]$ vanishes at every point in $\mathbb{Z}$. We may collect terms and rewrite $f$ as $$ f(x_1, \dots, x_n) = \sum_{i=0}^m x^i_n g(x_1, \dots, x_{n-1}), $$ for some functions $g_1,\dots,g_n\in \Bbb C[x_1,\dots,x_{n-1}]$. How do I proceed from here? I was trying to adapt an earlier proof with no success. |
I got this drwxrwxr-x 3 root tunnel 100 date and time . drwxr-xr-x 33 root root 860 date and time … -rwxrwxr-x 1 root tunnel 0 date and time enable-updates drwxrwxr-x 2 root tunnel 40 date and time interface -rwxrwxr-x 1 root tunnel 151 date and time resolv.conf Then I run sudo chown --recursive root:tunnel run/resolvconf sudo chmod --recursive 775 /run/resolvconf Then I get this drwxrwxr-x 3 root tunnel 100 date and time . drwxr-xr-x 33 root root 860 date and time … -rwxrwxr-x 1 root tunnel 0 date and time enable-updates drwxrwxr-x 2 root tunnel 40 date and time interface -rwxrwxr-x 1 root tunnel 151 date and time resolv.conf but after few second or reboot all is OVERWRITTEN flags and file resolv.conf and I get this again ls -al /run/resolvconf total 4 drwxrwxr-x 3 root tunnel 100 date and time . drwxr-xr-x 33 root root 860 date and time .. -rw-r--r-- 1 root root 0 date and time enable-updates drwxrwxr-x 2 root tunnel 40 date and time interface -rw-r--r-- 1 root root 151 date and time resolv.conf and I cant chattr chattr: Operation not supported while reading flags on /etc/resolv.conf here is cat for resolv.conf # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8) # DO NOT EDIT THIS FILE BY HAND – YOUR CHANGES WILL BE OVERWRITTEN | I was given the files for a mini linux, that boots directly into firefox. It works for all it should be doing, only that I do not get an internet connection. We have 3 DNS servers in the network, which all work. I can ping them, too. But when trying to ping google.de or wget google.de I get a bad address error. nslookup google.de works for some reason. I tracked the issue down to my resolv.conf on the booted system not having the same contents as the resolv.conf that I put into the .iso file. I tried understanding all the factors that go into creating and modifying resolv.conf. I'm not quite sure I got it all, but I definitely didn't find my solution there. So as a last ditch effort, I tried making the resolv.conf file immutable using :~# chattr +i /etc/resolv.conf When rebuilding and booting again to my surprise my file was renamed to resolv.conf~ and in its place was the same standard file that has been haunting me. The file contents make me believe it gets the information from the network itself. When starting the .iso in Virtualbox without internet access, my file is being kept as it is. I tried changing /etc/dhcp/dhclient.conf to not get the information from the net, by deleting domain-name-server and domain-name-search from the request part of the file. Didn't work unfortunately. I don't have the NetworkManager installed. The iso is based on Ubuntu 14.04. There is probably vital information missing. I'm happy to provide it. UPDATE: I think I found the file that clears resolv.conf. It seems to be /usr/share/udhcpc/default.script #!/bin/sh # udhcpc script edited by Tim Riker <[email protected]> [ -z "$1" ] && echo "Error: should be called from udhcpc" && exit 1 RESOLV_CONF="/etc/resolv.conf" [ - n "$broadcast" ] && BROADCAST="broadcast $broadcast" [ -n "$subnet" ] && NETMASK="netmask $subnet" case "$1" in deconfig) /bin/ifconfig $interface 0.0.0.0 for i in /etc/ipdown.d/*; do [ -e $i ] && . $i $interface done ;; renew|bound) /bin/ifconfig $interface $ip $BROADCAST $NETMASK if [ -n "$router" ] ; then echo "deleting routers" while route del default gw 0.0.0.0 dev $interface ; do : done metric=0 for i in $router ; do route add default gw $i dev $interface metric $((metric++)) done fi echo -n > $RESOLV_CONF # Start ---------------- [ -n "$domain" ] && echo search $domain >> $RESOLV_CONF for i in $dns ; do echo adding dns $i echo nameserver $i >> $RESOLV_CONF done for i in /etc/ipup.d/*; do [ -e $i ] && . $i $interface $ip $dns done # End ------------------ ;; esac exit 0 It's part of the udhcpc program. A tiny dhcp client, that is part of busybox Will investigate further. UPDATE2 AND SOLUTION: I commented the part out (#Start to #End), that seemingly overwrites the /etc/resolv.conf file and sure enough. That was the culprit. So an obscure script caused all this trouble. I changed the question to reflect, what actually needed to be known to solve my problem, so it would be easier to find for people with the same problem and so I could accept an answer. Thanks for the help here in figuring things out. |
I am using \documentclass{amsart} and want my table of contents subsections to be indented slightly beneath the sections. Right now, all the sections and subsections are equally flush to the left side. I still want the page numbers to be aligned though. What is the proper code? | I would like to obtain an advice regarding the TOC for an article. I wonder if the following serpent-like output caused by numbers of subsections being longer than those of sections is my mistake or is intended like that by amsart? If not, I'd like to know, even manually, how to correct it? I have tried a double title (one in square brackets having more space before the text) but no result. \documentclass{amsart} % \usepackage{titletoc} \usepackage{amsthm} \usepackage[english]{babel} \begin{document} \tableofcontents %% -------------------------- \section{First Movement} \subsection{Allegro con brio} \subsection{Allegro senza brio} \section{Second Movement} \subsection{Adagio} \subsection{Piu adagio} \subsection{Ancora piu adagio} \section{Third Movement: ``la sveglia''} \section{Finale} \subsection{Prestisisimo} \end{document} |
I have a HP Envy All in One, running Windows 8 I believe. I use mods such as optifine, potion counter, direction hud and togglesneak. Anyways, whenever I'm running around regularly, I get around 60 fps, whenever I start to PvP, it drops down to around 30 to 40. Anyways, how could I end . up getting more FPS? Would I need to upgrade anything? Need to get a new PC (because I'm most likely buying one soon anyways) Just let me know, thanks. | I'm a happy Minecraft player. I place my blocks, mine my coal, and generally nobody gets hurt. Lately though, those mean creepers have been sneaking up on me from behind, and killing me. Why? Because my framerate is so darn low. Adjusting the graphics option (Fancy to Fast) and the render distance help, but they are not enough. I have seen mention of outside optimizations and programs that people have made/used. What hacks, tricks, and mean mods can I use to improve my Minecraft FPS? |
In this example, a user can still access and set the variable using: obj = C() obj._x=10 varA = obj._x Even if we use __x instead of _x in below code, x still doesn't become private. So the only purpose of _x is to let the programmers know that it is not meant to be set directly via obj._x? class C: def __init__(self): self._x = None @property def x(self): """I'm the 'x' property.""" return self._x @x.setter def x(self, value): self._x = value @x.deleter def x(self): del self._x | Python gives us the ability to create 'private' methods and variables within a class by prepending double underscores to the name, like this: __myPrivateMethod(). How, then, can one explain this >>> class MyClass: ... def myPublicMethod(self): ... print 'public method' ... def __myPrivateMethod(self): ... print 'this is private!!' ... >>> obj = MyClass() >>> obj.myPublicMethod() public method >>> obj.__myPrivateMethod() Traceback (most recent call last): File "", line 1, in AttributeError: MyClass instance has no attribute '__myPrivateMethod' >>> dir(obj) ['_MyClass__myPrivateMethod', '__doc__', '__module__', 'myPublicMethod'] >>> obj._MyClass__myPrivateMethod() this is private!! What's the deal?! I'll explain this a little for those who didn't quite get that. >>> class MyClass: ... def myPublicMethod(self): ... print 'public method' ... def __myPrivateMethod(self): ... print 'this is private!!' ... >>> obj = MyClass() What I did there is create a class with a public method and a private method and instantiate it. Next, I call its public method. >>> obj.myPublicMethod() public method Next, I try and call its private method. >>> obj.__myPrivateMethod() Traceback (most recent call last): File "", line 1, in AttributeError: MyClass instance has no attribute '__myPrivateMethod' Everything looks good here; we're unable to call it. It is, in fact, 'private'. Well, actually it isn't. Running dir() on the object reveals a new magical method that python creates magically for all of your 'private' methods. >>> dir(obj) ['_MyClass__myPrivateMethod', '__doc__', '__module__', 'myPublicMethod'] This new method's name is always an underscore, followed by the class name, followed by the method name. >>> obj._MyClass__myPrivateMethod() this is private!! So much for encapsulation, eh? In any case, I'd always heard Python doesn't support encapsulation, so why even try? What gives? |
I am using Ubuntu 10.04 LTS. I want to upgrade to the latest version of Ubuntu. Is it possible? I read on this forum that I have to do a serial upgrading. If that is the case, will all my software installed previously be safe or do I have to reinstall them again? what happens to my data after upgrading? | What are the different ways I can use to upgrade Ubuntu from one release to another? |
I used to use gksudo gedit /etc/something.conf to edit system configuration files but this doesn't seem to work any more. Looks like there is no gksudo in 13.04. How can I add it back or what am I intended to use instead? | I have always recommended pressing ALT+F2 and typing for example gksu nautilus or gksudo nautilus both are equivalent; to run graphical programs with root privileges. However, I have just installed raring on a test system and this no longer works. gksu and gksudo are not installed as part of a default raring install; though they are in the repositories. In 12.04 at least gksudo was just a symbolic link to gksu The reasons I have always done this are because while it is often safe to use sudo under some circumstances it can cause problems with graphical applications because gksu has you running the program as root while with sudo you are running as yourself but with elevated privileges. This can mean you inadvertently change the owner of critical system files. This can cause problems. This reasoning is explained better here: Why was command removed from a fresh install and what should we be using instead? |
I have an LG Optimus 7 (not-rooted), and all my WiFi passwords are there. I want to view the saved WiFi passwords to transfer thm to my new Samsung Galaxy S3, but I don't know how. I tried to search on the Internet and Google play for an application that would allow me to view this information, but I can't find one. Is there any way for me to accomplish this? | I have an Android phone which is connected to a secured Wi-Fi hotspot. How can I find out the password of the hotspot from the phone? |
Tangents are drawn from the point ($\alpha$,$\beta$) to the hyperbola $3x^2 - 2y^2 = 6 $ and are inclined at angles A and B to the x -axis. If $\tan A. \tan B = 2$, prove that $\beta^2$=2$\alpha^2$ - 7. I tried the following concept,The points on Hyperbola from where tangent are drawn are $(\sqrt2*(\sec A),\sqrt3*(\tan A))$ & $(\sqrt2*(\sec B),\sqrt3*(\tan B))$ The two tangents are $\frac{\sec A}{\sqrt2}$-$\frac{\tan A}{\sqrt3}$=1 and $\frac{\sec B}{\sqrt2}$-$\frac{\tan B}{\sqrt3}=1$, I tried entering ($\alpha$,$\beta$) and using condition $\tan A. \tan B = 2$ but not able to get the result $\beta^2$=2$\alpha^2$ - 7. | Tangents are drawn from the point $(\alpha,\beta)$ to the hyperbola $3x^2-2y^2=6$ and are inclined at angles $\theta$ and $\phi$ to the $x-$axis.If $\tan\theta.\tan\phi=2,$ prove that $\beta^2=2\alpha^2-7$ The equation of the pair of tangents from the point $(\alpha,\beta)$ to the hyperbola $3x^2-2y^2=6$ is given by $(3x\alpha-2y\beta-6)^2=(3x^2-2y^2-6)(3\alpha^2-2\beta^2-6)$ When i simplify this expression,i get $(18+6\beta^2)x^2+(6\alpha^2-12)y^2-12xy\alpha\beta+24y\beta-36x\alpha+18\alpha^2-12\beta^2=0$ This is an equation of pair of lines and the angle between pair of lines $ax^2+2hxy+by^2=0$ is given by the formula $\frac{2\sqrt{h^2-ab}}{a+b}$ So $\tan(\theta-\phi)=\frac{2\sqrt{36\alpha^2\beta^2-(18+6\beta^2)(6\alpha^2-12)}}{18+6\beta^2+6\alpha^2-12}$ $\frac{\tan\theta-\tan\phi}{1+\tan\theta\tan\phi}=\frac{2\sqrt{\alpha^2\beta^2-(3+\beta^2)(\alpha^2-2)}}{1+\beta^2+\alpha^2}$ $\frac{\tan\theta-\tan\phi}{3}=\frac{2\sqrt{\alpha^2\beta^2-(3+\beta^2)(\alpha^2-2)}}{1+\beta^2+\alpha^2}$ I am stuck here.I do not know,how to prove it further. |
Popular science literature is replete with the necessity for superstring theories to live in at least 10 dimensions, requiring at least 6 of them to be compactified so that they are not observable. But can they predict that 4 dimensions are not compactified? Or conversely, for a superstring theory in e.g. 10 dimensions, are there arguments against compactifying 7 dimensions? or only 5? Arguments other than being ruled out by observation I mean. My question has been marked as a duplicate of . Only the answer is relevant to my question. It quotes a paper by Karsh and Randall which seems to address my exact question: We propose a new selection principle for distinguishing among possible vacua that we call the “relaxation principle.” The idea is that the universe will naturally select among possible vacua through its cosmological evolution, and the configuration with the biggest filling fraction is the likeliest. We apply this idea to the question of the number of dimensions of space. We show that under conventional (but higher-dimensional) FRW evolution, a universe filled with equal numbers of branes and antibranes will naturally come to be dominated by 3-branes and 7-branes. We show why this might explain the number of dimensions that are experienced in our visible universe. But this is far too advanced for me as I can barely recognise buzzwords! And answer A10723 is of rather low quality, just a vague description of the goal of the paper which does not give any hindsight into the physics in there. In any case, this also mean that the other question, , mine is marked as a duplicate of, has even poorer answers than they look like at first glance. Following the link on the page of Karsh and Randall paper turns out several citations which look to address my question and Q10075, but again at a level I can't grasp. | I've often heard the argument that having 3 spatial dimensions is very special. Such arguments are invariably based on certain assumptions that do not appear to be justifiable at all, at least to me. There is a on Wikipedia. For example, a common argument for why >3 dimensions is too many is that the gravitational law cannot result in stable orbital motion. A common argument for <3 dimensions being too few is that one cannot have a gastrointestinal tract, or more generally, a hole that doesn't split an organism into two. Am I being overly skeptical in thinking that while the force of gravity may not be able to hold objects in stable orbits, there most certainly exist sets of physical laws in higher dimensions which result in formation of stable structures at all scales? It may be utterly different to our universe, but who said a 4D universe must be the same as ours with one extra dimension? Similarly, isn't it very easy to conceive of a 2D universe in which organisms can feed despite not having any holes, or not falling apart despite having them? For example, being held together by attractive forces, or allowing certain fundamental objects of a universe to interpenetrate, and thus enter a region of the body in which they become utilized. Or, conceive of a universe so incomprehensibly different to ours that feeding is unnecessary, and self-aware structures form through completely different processes. While I realise that this is sort of a metaphysical question, is 3+1 dimensions really widely acknowledged to be particularly privileged by respected physicists? |
When linking some object files together I get a bunch of errors like: obj-ia32/ShadowRoutine.o: In function `InitializeMap(unsigned int*)': ShadowRoutine.cpp:(.text+0x0): multiple definition of `InitializeMap(unsigned int*)' obj-ia32/ShadowRoutine.o:ShadowRoutine.cpp:(.text+0x0): first defined here with compilation and linking commands of: g++ -DBIGARRAY_MULTIPLIER=1 -Wall -Wno-unknown-pragmas -fno-stack-protector \ -DTARGET_IA32 -DHOST_IA32 -DTARGET_LINUX -I../../../source/include/pin \ -I../../../source/include/pin/gen -I../../../extras/components/include \ -I../../../extras/xed-ia32/include -I../../../source/tools/InstLib -O3 \ -fomit-frame-pointer -fno-strict-aliasing -Wno-unused-variable \ -Wno-unused-function -I. -Ishadow-memory -m32 -c \ -o obj-ia32/ShadowRoutine.o ShadowRoutine.cpp g++ -DBIGARRAY_MULTIPLIER=1 -Wall -Wno-unknown-pragmas -fno-stack-protector \ -DTARGET_IA32 -DHOST_IA32 -DTARGET_LINUX -I../../../source/include/pin \ -I../../../source/include/pin/gen -I../../../extras/components/include \ -I../../../extras/xed-ia32/include -I../../../source/tools/InstLib -O3 \ -fomit-frame-pointer -fno-strict-aliasing -Wno-unused-variable \ -Wno-unused-function -I. -Ishadow-memory -m32 -c \ -o obj-ia32/Jikes.o Jikes.cpp g++ -shared -Wl,--hash-style=sysv -Wl,-Bsymbolic \ -Wl,--version-script=../../../source/include/pin/pintool.ver \ -m32 -o obj-ia32/Jikes.so obj-ia32/ClientReq.o obj-ia32/Server.o \ obj-ia32/ShadowRoutine.o obj-ia32/FncnMap.o obj-ia32/Trace.o \ obj-ia32/Jikes.o obj-ia32/ClientReq.o obj-ia32/Server.o \ obj-ia32/ShadowRoutine.o obj-ia32/FncnMap.o obj-ia32/Trace.o \ -L../../../ia32/lib -L../../../ia32/lib-ext -L../../../ia32/runtime/glibc \ -L../../../extras/xed-ia32/lib \ -L/home/karl/r/git/pin/source/tools/Jikes/zmq/inst/lib \ -lpin -lxed -lpindwarf -ldl -lzmq The only two object files with InitializeMap are Jikes.o and ShadowRoutine.o: $ nm obj-ia32/Jikes.o | grep InitializeMap U _Z13InitializeMapPj $ nm obj-ia32/ShadowRoutine.o | grep InitializeMap 00000000 T _Z13InitializeMapPj $ nm obj-ia32/* | grep InitializeMap U _Z13InitializeMapPj 00000000 T _Z13InitializeMapPj So why am I getting "multiple definitions of InitializeMap" if it's only "defined" in one object file and "undefined" in the only other object file that required it using extern? This is what the declarations, definitions, and uses look like: $ grep -r InitializeMap * Jikes.cpp: if (rtn_name == "sysInitializeMap") { RTN_INSERT_1(InitializeMap); Binary file obj-ia32/Jikes.o matches Binary file obj-ia32/ShadowRoutine.o matches ShadowRoutine.cpp:VOID InitializeMap(ADDRINT *smID) { init_map(*(int*)smID); } ShadowRoutine.hpp:VOID InitializeMap(ADDRINT *smID); where both the cpp files #include "ShadowRoutine.hpp". EDIT: My question is why does the linker command (the third g++ command in the second code snippet above) not work even though nm says that the function is only defined in the text of ShadowRoutine.o and undefined in Jikes.o? | Why does C++ have header files and .cpp files? |
Below I have provided an example of a checkbox group including a parent checkbox in an indeterminate state. Some of the child nodes in the Tall Things tree are selected and some are not, therefore Tall Things is presented in an indeterminate state: When the user clicks on the indeterminate checkbox, what should happen? Should the checkbox be checked, or should it be cleared? More importantly, why? | There is a hierarchy of selectable items, let's say a parent and two children. All three items have checkboxes. When both children are checked, the parent's checkbox is also checked. When both children are unchecked, the parent's checkbox is also clear. When only one of the children is checked, the parent is half-checked (color fill or a diagonal inside the checkbox). This relationship works both ways - the parent's checkbox works as a select/clear all for the children checkboxes. What should happen when users click the half-checked parent - check or uncheck? Or rather, what factors might influence this decision? |
I found there's loads of applications to choose from there it seems like all of them. You've got to add the ppa, update then install the applications. This can be pretty cumbersome if you plan on installing a few with the terminal. Is there a launchpad application that replaces the ubuntu software centre? Does the synaptic package manager index everything in launchpad? maybe that's what I'm looking for let me know cheers :) After asking | is a fantastic repository of packages, and one that I use often to install packages that are not included in the main repository. Thus far, I've always simply browsed to a package page (e.g. ) and manually downloaded the Deb file, which kicks off the Ubuntu Software Center and lets me easily install the package. It would be even cooler if I could use LaunchPad.net as a regular apt source, i.e. by doing something like this: echo 'deb https://launchpad.net/ubuntu natty amd64' | sudo tee -a /etc/apt/sources.list Does anyone know what the correct sources line would be? |
Pretty new to Blender, I'm trying to learn how to make a studded wall. How do I use the array modifier to use imperial units? For example, I would like to create a stud, and have them spaced 16 inches on center a set distance. Thank you much! Sorry if this is a duplicate, I asked this question yesterday but it was closed, so I'm asking again. | Pretty new to Blender, I'm trying to learn how to make a studded wall. How do I use the array modifier to use imperial units? For example, I would like to create a stud, and have them spaced 16 inches on center a set distance. Thank you much! Edit I've accepted the below answer, however, I had another issue I had to fix. The culprit was that when I scaled the initial object, I didn't apply the scale. Because I didn't apply the scale before the modifier, it wasn't working as expcted. Thank you much to for helping me through this issue! |
Given a topological space $X$ and a path $p : [0, 1] \to X$ such that $p(0) \neq p(1)$, does there always exist an injective path $p' : [0,1] \to \operatorname{im}p$ such that $p'(0) = p(1)$ and $p'(1) = p(1)$? For intuitive examples of paths we could "cut out" the loops which occur in $p$, but are there pathological examples of paths in which this technique cannot be applied? Otherwise, is there a Theorem that guarantees the existence of $p'$, even for only certain "nice" classes of paths $p$? For any $X$ that satisfies this property, any subspace of $X$ is path-connected if and only if every two points are joined by an injective path. What about the special case where $X = \mathbb{R}^n$? | Let $X$ be a path-connected topological space, i.e., for any two points $a,b\in X$ there is a continuous map $\gamma\colon[0,1]\to X$ such that $\gamma(0)=a$ and $\gamma(1)=b$. Note that beyond continuity little is required about $\gamma$. Is it always possible to make $\gamma$ a simple (=injective) curve? (Of course we consider only the case $a\ne b$). If the answer depends on $X$, what are some mild sufficient conditions on $X$? If $X$ is sufficiently nice, e.g., an open subset of $\Bbb R^n$, the answer is "yes"; more generally, what one would call "locally simplepath-connected" suffices (the set of points reachable from $a\in X$ by a simple curve is both open and closed). Also, for arbitrary $X$ it is clear that a single instance of self-crossing can be short-cut. But for infinitely many possible short-cuts the situation may become somewhat hairy, I'm afraid. EDIT: To avoid Mike Miller's counterexample (indiscrete topology on $X$ with $|X|<|\Bbb R|$), let's at least assume that $X$ is Hausdorff. At any rate, $|X|\ge|\Bbb R|$ is a necessary condition - I am still looking for "as mild as possible" sufficient conditions ... |
I have a HDD capacity of 1.32 TB. I have more space left unused in my / partition. I want to extend /home by shrinking / without losing any data. | Previously, I have installed Windows 7 on my 320 GB laptop with three partitions 173, 84 and 63 GB each. The 63 GB partition was where the Windows was installed. The rest were for file containers. Now I changed my OS to Ubuntu 12.04 LTS. I installed Ubuntu by replacing the entire Windows 7 on the 63 GB partition. The rest of the partitions remain as an NTFS Windows partition and I can still access them both (the 173 and 84 GB partitions). Now I want to change the two partitions of Windows into an Ubuntu format partitions plus most importantly, I want to extend the 63 GB partition to more than a 100 GB because at the moment I am running out of disk space. Whenever I try to install any application, especially using wine, it always complains for a shortage of disk space. How do I do the extending activity before I entirely format my laptop again and lose all the important files on my partitions? |
Changed some names to be more accurate. I have an app that I can run from terminal. The app exists in a folder in my home directory named ZereneStacker. The name of the app is also ZereneStacker. Right now, I only know how to run it from terminal and I do that like this. cd ZereneStacker ./ZereneStacker.bsh It runs fine this way. I created a .desktop file in /usr/share/applications and named it zerene.desktop. I made it executable. Here is the contents of zerene.desktop: [Desktop Entry] Version=1.0 Name=Zerene Focus Stacker Comment=Focus Stacker GenericName=Focus Stacker Exec=./ZereneStacker.bsh Path=~/ZereneStacker Terminal=false Type=Application Categories=Photography StartupNotify=true I stole most of this from another working .desktop file. When I try and click on the icon in /usr/share/applications, I get "There was an error launching this application". Since I know it loads fine when I do it form the terminal command line as outlined above, I know the problem is with what I did and not the program. Sorry I tried to be generic in the original message to "simplify" only to have that backfire on me now. | I am using Ubuntu 13.04, I recently downloaded Fritzing .tar.bz2 , which I extracted it & there is one .sh file, which I have to execute everytime from terminal to run the application. My question is, Is it possible to create a launcher of Fritzing & make it show up in Applications in Dash ? If it is, then please help me out with steps. Thank you. |
I've recently bought a tablet. Since it's a 'local' brand, I don't expect to see any updates, and I was wandering how could I find some other (cyanogen, or other) ROMs to update the software myself (currently, it's 4.2.2). Do I search for roms that match the CPU/resolution/ram/... does it need to match every specification, or only in part? | There are several reasons to be looking for a ROM: Upgrading or downgrading your stock ROM Looking for firmware from a different region/language Flashing a custom ROM for different features, removing bloat, etc. But where can one find ROMs in the first place? What sites are likely to have the ROM I need? ; please add to the wiki answer instead of posting separate answers. See also: |
Let $f:\mathbb{R}\to \mathbb{R}$ and denote $A_f=\{(x,f(x)),x\in\mathbb{R}\}$. I've proved that if $f$ is continuous, then $A_f$ is closed. But I have no clue for the other direction. Does $A_f$ closed also imply $f$ continuous? Thanks a lot~ | I tried looking up a question regarding graphs of continuous functions on this site, but all the ones I found consider functions from $\mathbb{R}$ into $\mathbb{R}$. I have been pondering the following question: given a general topological spaces $X, Y$, and a function $f: X\to Y$, when does $Graph(f)$ closed in $X\times Y$ imply that $f$ is continuous. By the closed graph theorem, this is true whenever $X$ and $Y$ are both Banach spaces. Also, it is fairly easy to prove that whenever $Y$ is a Hausdorff space and $f$ is continuous, then $Graph(f)$ is closed, but I do not think that the converse is true, so I am trying to find an example where $X$ is some topological space, $Y$ a Hausdorff space, $f: X\to Y$ a function with a closed graph in $X\times Y$, but who fails to be continuous. As of yet I have not been able to find such a counterexample, partially because I have no clue where to look for such a counterexample. I would really appreciate getting some directions to go in. |
I want to excecute the following command over a ssh connection: tmpValue=$(cat /var/run/jboss-as/jboss-as-standalone8.pid) && top -b -U jboss -n 1 |grep $tmpValue |awk '{print $9}' This command is working on my target machine. Now I want to use this command from a different machine and execute it via ssh, so what I have done is this: ssh jboss@myTargetServer tmpValue=$(cat /var/run/jboss-as/jboss-as-standalone8.pid) && top -b -U jboss -n 1 |grep $tmpValue |awk '{print $9}' The result is cat: /var/run/jboss-as/jboss-as-standalone8.pid: No such file or directory Usage: grep [OPTION]... PATTERN [FILE]... Try 'grep --help' for more information. Whats wrong with my call? | I have the following in a script for server in ${servers[@]}; do echo ${server} ssh user@${server} "for i in /tmp/foo* ; do echo ${i}; done" done But it doesn't work. Weird thing, I see $I amount of return lines. So if I have ten files, I see ten blank lines. |
Are there any airlines that offer a child-free flights? I would happily pay more for a ticket for an adult-only flight. I'm not looking for tips on what to do if you find yourself on a flight with children. I would very much like a child-free flight. There is no such thing as a quiet zone on commercial airlines and noise suppressing headphones cannot drown out screaming children who drown out the engines. | I was wondering whether there are any flights for people who can't stand children or don't want to be around them. I'm sure there is a demand. By child-free, I mean child-free flights, child-free zones, or other options. Can I request a child-free option on a regular flight to have no kids sitting nearby? How much does it cost to have a child-free flight compared to a normal one? |
If opponent only can move between the two diagonal squares in the "open" corner, does he lose? How many times can he makes these fruitless moves? | What is the term for a stalemate in Checkers? What are the official conditions for a "no winner game"? |
Let $ a_n $ be a non-negative sequence, such that $ \sum_{n=1}^{\infty}\sqrt{a_{n}} $ converge. Is it true that $ \sum_{n=1}^{\infty}a_{n} $ converge? I think that it is. But I want to make sure because it appeared in my final exam. Here is my reasoning: Since $ \sum_{n=1}^{\infty}\sqrt{a_{n}} $ converges, $ \sqrt{a_{n}}\underset{n\to\infty}{\to}0 $ and thus $ a_{n}\underset{n\to\infty}{\to}0 $. So there exists some $ n_0 $ such that, for all $ n>n_0$, it follows that $ 0\leq a_{n}<\frac{1}{2} $. Thus, for each $ n>n_0 $ we have $$ a_{n}<\sqrt{a_{n}} .$$ So, from the comparison test, we get the convergence of $$ \sum_{n=1}^{\infty}a_{n}. $$ Do you agree? | Let $(a_n)$ be a sequence of positive terms and suppose that $\sum_\limits{n=0}^{\infty} a_n$ converges. Show that $\sum_\limits{n=0}^{\infty} a_n^2$ converges. This is in the section on the Comparison Test so that must be what I'm supposed to use. But I don't see how. $(a_n)^2$ might be smaller or larger than $a_n$ depending on $a_n$. And I can't use the Comparison Test with some other series because there's no info here about how fast $\sum a_n$ converges. Hmm. Any hints? |
In American football, it seems that some people would say: He caught a pass. To my knowledge, a "pass" is an action. So, the sentence would translate to: He caught an action. Is my analysis wrong? | The context is soccer (association football) and the sentence in question is: The forward received the ball from the midfielder's pass. I have already ask about this and received alot of good answers, and I tried to leave it at that. But then the World Cup 2014 is upon us, and I am starting to have doubts about this football usage of "from", to the point that I have semi-nightmares about it. The use of "from" in the football example continues to bother me. I seem to disagree (subconsciously) about how a ball (physical object) could be "from" a pass (action) unless that action creates that object. Some people were hit by debris from the explosion. The use of "from" in "debris from the explosion" makes excellent sense to me, because the explosion does create the debris. But in soccer/football, the ball cannot possibly be "created" by a pass. Is there any non-football usage of "from" similar to my football example sentence? |
Why does the $\lim \sum{n^{(1/n)}-1}$ diverge as $n\rightarrow \infty$? I suspected it would converge as $\lim {n^{(1/n)}}=1$ as $n\rightarrow \infty$ but computation show otherwise. So, now I am trying to show the partial sums are unbounded but didnt get far. | Let $a_n=\sqrt[n]n-1$. Does $\sum_{n=1}^\infty a_n$ converge? |
I'm new in Blender, i'm doing a dome with tow windows, but i have problems solving the boolean between the dome and the window. When i apply the subdivision surface it goes bad, i know tehere are prblems with the topolgy. Please, any advice? Thanks! Bad mesh | I would like to add an edge loop around each one of these windows and are not 100% sure on the best way to do it even after watching some videos. If someone could point me in the right direction that would be great. Thanks. |
Given this theorem: For every prime 𝑝 and all integers a, b, if p|ab, then p|a or p|b Prove: Let 𝑥 ∈ ℤ and 𝑝, 𝑞 be distinct primes. Then p|x and q|x if and only if pq|x I have already proven if p|x and q|x then pq|x. Now I need to prove it the other way around, if pq|x then p|x and q|x I have this: We have pq|x which means x = pqn, where n is some integer Where do I go from here? | Prove: If $a\mid m$ and $b\mid m$ and $\gcd(a,b)=1$ then $ab\mid m$ I thought that $m=ab$ but I was given a counterexample in a comment below. So all I really know is $m=ax$ and $m=by$ for some $x,y \in \mathbb Z$. Also, $a$ and $b$ are relatively prime since $\gcd(a,b)=1$. One of the comments suggests to use , i.e., $aq+br=1$ for some $q,r\in\mathbb{Z}$. Any more hints? New to this divisibility/gcd stuff. Thanks in advance! |
For some reason, I can't make a ".theme" or ".icon" file in the Ubuntu file browser to change my theme, or for some reason they are not shown. When I try to make another one it always tells me that there is already a file called ".icon" or ".theme" but if I search for them in the search bar they are not shown. My Linux version is Ubuntu 18.04 and I am running it on a Lenovo t420s with a i5 2400.. something. Please Help. | How do you show a hidden folder (whose name starts with .) in File Manager a.k.a. Nautilus on Ubuntu? I am somewhat new to Ubuntu and can't seem to find the "view" menu. |
I have posted a question about the use of sDNA in ArcGIS. It is said the problem is caused by non-ascii characters. I tired to modify the shapefile and kept the Object ID and Shape length only. However, the analysis still failed. Here is the attribute table of the data and the steps I tried. | I am trying to perform centrality analysis with sDNA with ArcGIS Pro (ver. 2.7.1). However, I have failed to run the Preparation & Integral Analysis in sDNA with the same reason. What is the problem and What should I do? |
im try to take data from html form and transfer it to my DB using post and php. Whenever I do, the data changes to something unfamiliar to me. I'm very new to programming, please help me. my html code: <form action="insert.php" method="post"> <tbody> <tr> <td width="20%">privet name</td> <td><input type="text" id="privetname" name="fname" size="16"></td> </tr> <tr> <td width="20%">&nbsp;last name</td> <td><input type="text" id="lastname" name="lname" size="16"></td> </tr> <tr> <td width="20%">&nbsp;phone</td> <td><input type="text" id="phone" name="phone" size="16"></td> </tr> <tr> <td width="20%">&nbsp;email</td> <td><input type="email" id="email" name="email" size="16"></td> </tr> <tr> <td width="20%">&nbsp;birthday</td> <td><input type="date" id="birthday" name="birthday"></td> </tr> <tr> <td width="20%">&nbsp;anniversary</td> <td><input type="date" id="anniversary" name="anniversary"></td> </tr> <tr> <td><button type="submit"><font size="+1">Create Customer</font></button></td> </tr> </tbody> </form> my php code: $sql="INSERT INTO customer (fname, lname, phone, email, birthday, anniversary) VALUES ('$_POST[fname]','$_POST[lname]','$_POST[phone]','$_POST[email]','$_POST[birthday]','$_POST[anniversary]')"; /* ,'$_POST[birthday]','$_POST[anniversary]' */ | I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1. Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur? This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2. |
As far as I am aware no other countried are used an article before them, but people usually refer to Ukraine as "The Ukraine". Why? | Possible Duplicate: Hearing the Ukraine used to make me unsure whether Ukraine was really a country. Now though I have realized Ukraine to be a country on the same level as Austria, for instance, I still don't understand why it is often the Ukraine in English, but never the Austria or the Poland. Where did that odd phrase come from, and why is it in use? |
I want to install some drivers for my graphics card. usually when I do that something goes wrong, I then try to fix it, something else goes wrong. I finally end in failure and have a destroyed system and a non working driver. I want to have something like a checkpoint, or a full system image as backup. something to go back to if I fail. is there any way to do something like this? how to make a backup image and how to restore it if needed? | I'm a new Linux user. I've reinstalled my Wubi from scratch at least ten times the last few weeks because while getting the system up and running (drivers, , etc.) I've broken something (X, grub, unknowns) and I can't get it back to work. Especially for a newbie like me, it's easier (and much faster) to just reinstall the whole shebang than try to troubleshoot several layers of failed "fixing" attempts. Coming from Windows, I expect that there is some "disk image" utility that I can run to make a snapshot of my Linux install (and of the boot partition!!) before I meddle with stuff. Then, after I've foobar'ed my machine, I would somehow restore my machine back to that working snapshot. What's the Linux equivalent of Windows disk imagers like or ? Note: I found a similar question: |
Protection is an ability that grants an object or player several benefits, including: 702.16c A permanent or player with protection can’t be enchanted by Auras that have the stated quality. Such Auras attached to the permanent or player with protection will be put into their owners’ graveyards as a state-based action. (See rule 704, “State-Based Actions.”) This ability is usually less relevant because when enchantment auras are cast they target, and protection prevents targeting as well. However, if an enchantment aura enters the battlefield without being cast (such as from a flicker effect or ), the comprehensive rules say: 303.4f If an Aura is entering the battlefield under a player’s control by any means other than by resolving as an Aura spell ... that player chooses what it will enchant as the Aura enters the battlefield. The player must choose a legal object or player according to the Aura’s enchant ability and any other applicable effects. Does the "any other applicable effects" clause prevent me from putting an aura onto a protected permanent? At first I thought yes because protection specifically says 'can't be enchanted'. But then I re-considered, as I'm more leaning towards the interpretation that protection prevents ongoing enchantment, not the act of putting an enchantment onto something. For a specific example, if my opponent has a creature with protection from blue, and I use to flicker a that is currently on the battlefield, can I choose my opponents pro blue creature to enchant with Reality Acid? Knowing that it would immediately slide off as a state based action, but me being ok with that due to Reality Acid's triggered ability. This question seems close: , but I think is subtly different as the card in question specifically removes the 'can't be enchanted' clause which is crucial to my question here I think. | I have a question about a new Born of the Gods card. The card is called . It has the text that says: Whenever Silent Sentinel attacks, you may return target enchantment card from your graveyard to the battlefield. I was listening to podcast with Judge Joe Bono. In that episode he says that Silent Sentinel could attach a Enchantment Aura to a creature that was protected from the color of the aura. He then says that it would just drop off immediately. (This was right around the 1 hour mark in the show.) I got to thinking about this and I wondered if any of the effects of the Enchantment would have any effect before they dropped off. Here is an example to illustrate: My opponent has a in play. I have a Silent Sentinel in play along with 7 Swamps. I have a in my graveyard. In my combat phase, I attack with my Silent Sentinel. This allows me to bring back a Quag Sickness from my graveyard. I attach Quag Sickness to the White Knight. (Note: Because bringing an aura back with Silent Sentinel it does not require targeting to attach it. So it can attach to White Knight despite it having protection from Black). Now the arua will fall off right away, but before it falls off does any of the effects of it do anything? (Meaning could it kill the White Knight.) If the Quag Sickness in this example does not do anything, is there a scenario that would? |
Is there any UI in ubuntu like the one in Windows to kill the processes forcefully. My google chrome application is stuck and i can't close it, need to do it forcefully.Please help ! | I am looking for system monitoring tools which are GUI and CLI or web-based which include basic functions such as: CPU Usage Ram Usage Swap Usage Disk Usage ( Space / I/O ) Heat Monitoring I know there are many tools I can use, but I am looking for a single tool that has these basic functions. |
Is she not a girl? Isn't she a girl? Am I not here? Am not I here? Are tey all correct or right structured? | (1) Does he not know? (2) Doesn't he know? I don't usually see and hear questions formed in the first style. I was even surprised to know that it is grammatically correct. And actually it is the most "proper" way to form an interrogative sentence. shows that the first style was much more popular before than now. What are your suggestions on choosing between these styles? And I will probably add the third one. (3) He does not know? EDIT: The answers have explained how to form a question, but have not actually provided an account on the usage of the first two forms. Especially I'm interested in the first form: does it sound formal, is it used in speech or only in writing, et cetera. |
Which format is more correct when writing date in UK? "5 January 2019" or "5th January 2019" and why? Should I use "th" at the end? What is the best way to write it? | How do you spell the following date: December 6 (AmE) 6 December (BrE) Do you spell this date as 'December six' or 'December the sixth' in American English? And in British English, do you spell it as 'Six December' or 'The sixth of December'? |
What I mean is, suppose white light falls on a red object and is reflected, so when we see the reflected light reaches our eyes we see it as red (probably because its wavelength corresponds to red). But let's say that this reflected light falls on a purple object and then reaches our eye. What color would we perceive of the purple object? If the answer is purple, then where did the extra energy come from? ( as purple light has more energy than red) | When white light falls on an object the body absorbs all colors of light and reflects some colors of light which we see the object to be.For eg.A red ball reflects red color and absorbs the rest colors.So,if I throw green light on a red ball the ball will absorb that green light.Now,will the part on which the light falls must appear black as it absorbs all the light and reflects no light.But this does not happen in reality(I have experimented using laser light).Why? |
I'll start by explaining my scenario: I am creating a MMORPG and I want to get a better understanding of the most efficient way to store items in an inventory. From my research, I found that most games have an INVENTORY table where the rows have the ITEM_ID, the ITEM_QUANTITY, the USER_ID, and the SLOT_ID. I'm thinking that this table could potentially have millions of rows. So If I use a simple statement such as: SELECT ITEM_ID FROM INVENTORY WHERE USER_ID = 25; then how does the database really "find" the result to return? Does it have to "loop" through every single record until it finds the match? My concern is that, if that is in fact the way it is done, then wouldn't some SELECT FROM WHERE statements take forever? Thanks, Ian | Given that indexing is so important as your data set increases in size, can someone explain how indexing works at a database-agnostic level? For information on queries to index a field, check out . |
Red, green, and blue are the primary colors of light—they can be combined in different proportions to make all other colors. For example, red light and green light added together are seen as yellow light. This additive color system is used by light sources, such as televisions and computer monitors, to create a wide range of colors. When different proportions of red, green, and blue light enter your eye, your brain is able to interpret the different combinations as different colors. My question is can the eye distinguish between light of the pure wavelength corresponding to yellow(monochromatically yellow) and a mixture of red and green light that also produces the sensation of yellow in our eyes? The question is related to the question asked here: But my specific question is whether the eye can distinguish between the mixture and a pure wavelength of purple. | In music, when two or more pitches are played together at the same time, they form a chord. If each pitch has a corresponding wave frequency (a pure, or fundamental, tone), the pitches played together make a , which is obtained by simple addition. This wave is no longer a pure sinusoidal wave. For example, when you play a low note and a high note on a piano, the resulting sound has a wave that is the mathematical sum of the waves of each note. The same is true for light: when you shine a 500nm wavelength (green light) and a 700nm wavelength (red light) at the same spot on a white surface, the reflection will be a superposition waveform that is the sum of green and red. My question is about our perception of these combinations. When we hear a chord on a piano, we’re able to discern the pitches that comprise that chord. We’re able to “pick out” that there are two (or three, etc) notes in the chord, and some of us who are musically inclined are even able to sing back each note, and even name it. It could be said that we’re able to decompose a Fourier Series of sound. But it seems we cannot do this with light. When you shine green and red light together, the reflection appears to be yellow, a “pure hue” of 600nm, rather than an overlay of red and green. We can’t “pick out” the individual colors that were combined. Why is this? Why can’t we see two hues of light in the same way we’re able to hear two pitches of sound? Is this a characteristic of human psychology? Animal physiology? Or is this due to a fundamental characteristic of electromagnetism? |
I need help with this differential geometry problem dealing with Gaussian curvature and mean curvature Given an ellipsoid with parametric representation $(a\cos u\cos v, b\cos u \sin v, c\sin u)$ compute its Gaussian curvature and mean curvature. (Hint: Compute $E,F,G$ first and $L, M, N$ second then Weingarten map (Shape operator). The Gaussian curvature and the mean curvature are the determinant and the trace of the Weingarten map (Shape operator). | I am trying to review, and learn about how to compute and gaussian and mean curvature. Given $\frac{x^2}{a^2} + \frac{y^2}{b^2} + \frac{z^2}{c^2} = 1$, how can I compute the gaussian and mean curvatures? This is what I have so far, $$K(u, v) = \frac{a^2 b^2 c^2}{[c^2 \sin^2(v) (a^2 \sin^2(u)+b^2 \cos^2(u))+a^2 b^2 \cos^2(v)]^2}$$ Please help me out. |
What is the value of $187^2 \mod 100$? | I was wondering if there is a simpler way to find the last to digits of a power such as $3^{45}$. I reduced it modulo 100 to get the answer, which is 43. But I was curious if there was a simpler, or more eloquent way to get this result. Here's my method: Using the fact that $3^4=81\equiv -19 \pmod{100}$ and $19^5=2,476,099\equiv -1 \pmod{100}$ $$ 3^{45}\equiv 3(3^4)^{11}\equiv 3(-19)^{11}\equiv 3(-19)(19^5)^2\equiv 3(-19)(-1)^2 \equiv -57 \equiv 43 \pmod {100} $$ I just felt like this was sort of a messy way to find out that the last two digits are 43. |
Recently I've been getting a lot of work with T-shirts and they ask me to distress t-shirts. This is a simple matter if the graphic is only one color, but occasionally I will get a graphic that's 4 or more colors and layered on top of each other. I will then have to apply a distressed texture to each separate shape. This can get tedious and time consuming. Not to mention the texture file is huge because it's distressed and creates a lot of points. Do you guys know of a way that I can place a distressed texture on top of a vector graphic with multiple colors and shapes and just punch through or knockout all the way to the back of the stack? I hope that makes sense. Here is an example. There is white around the letters and the filled in areas on the face are white as well. I want the distressed graphic to punch through all the way, but when I use the minus front, it ends up only punching through some shapes or it all fuses together as one big mess. If it helps the t-shirts will be screen printed. Edit - Thanks for the answer, it works. Here is a rundown of how I created it Copied the graphic, and fused everything together as one solid shape. Placed distressed graphic over solid shape graphic. Create clipping mask of that. Place that over the original with the option clip checked. | I am trying to do an opacity mask and it is driving me crazy. Bascially I have a layer of ice. It's four different pictures of ice overlapping each other so it looks like a whole bunch of ice. I want to have it fade in from both sides (left and right) until it is completely opaque in the middle. I've select all of the pictures and chosen 'Make Opacity Mask' from the Transparency Panel and it disappears but then I don't know how to manipulate the opacity. In the Transparency panel it doesn't show a picture of what I'm working with so I can't simply click next to it to create the opacity mask like I've seen in tutorials. I've also tried to overlay a rectangle over the objects, choose them all then try 'Make Opacity Mask' but that didn't work either. Any ideas? Thanks. |
Where can I find / download the source code that is used for the Markdown editor used by Stack Overflow? This is what it looks like: | Where is the open source project for the WMD editor used on this site? |
Example: Player 1 has a Mirror Entity in play (Secret: When your opponent plays a minion, summon a copy of it). He also has 3 minions on the board. Player 2 starts his turn with no minions and plays a Mind Control Tech (Battlecry: If your opponent has 4 or more minions, take control of one at random). What happens? Extra credit: what happens if Player 2 started with 3 minions before playing his Mind Control Tech? Just trying to wrap my head around the mechanics. Thanks. Edit: this is different from the link because the accepted answer on that question is not relevant to Secrets and does not go into detail on their usage. In that answer, quote: "According to Lead Designer Eric Dodds, events such as Deathrattles that are triggered simultaneously will occur in the order in which the related cards were played.". Secrets don't enter the stack when they were played, but rather as they are triggered which is a subtle but important point to this question (and something I learned through the accepted answer on here and some of the commentary from Waterseas). | I was using and my opponent has a . I attacked Sylvanas, fearing that the Deathrattle will take control of one Hyena. I feel lucky, because it did not happen. I want to know if there are some general rules of effect precedence. Has Blizzard published something about this? Are there articles teaching about precedence? Please note, I want guidance about effect precedence in general, not just about Deathrattle. |
I am trying to use regex to get rid of strings between specific characters, for example "[" and "]": input = "There is a [blue] cloud on top of that [big] elephant"; desiredOut = "There is a cloud on top of that elephant"; // this is what i want But if I use regex to replace what is between "[" and "]" I remove everything between the first and last of this characters: string input = "There is a [blue] cloud on top of that [big] elephant"; string regex = "(\\[.*\\])" ; string actualOut = Regex.Replace(input, regex, ""); actualOut = "There is a elephant" // this is what i get Any clues on how to remove the stuff between inmediate delimiters? thanks. | I have this gigantic ugly string: J0000000: Transaction A0001401 started on 8/22/2008 9:49:29 AM J0000010: Project name: E:\foo.pf J0000011: Job name: MBiek Direct Mail Test J0000020: Document 1 - Completed successfully I'm trying to extract pieces from it using regex. In this case, I want to grab everything after Project Name up to the part where it says J0000011: (the 11 is going to be a different number every time). Here's the regex I've been playing with: Project name:\s+(.*)\s+J[0-9]{7}: The problem is that it doesn't stop until it hits the J0000020: at the end. How do I make the regex stop at the first occurrence of J[0-9]{7}? |
I ran this command : sudo apt-get install mysql-server and I got this as the output: Reading package lists... Done Building dependency tree Reading state information... Done The following additional packages will be installed: libevent-core-2.1-6 mysql-server-5.7 mysql-server-core-5.7 Suggested packages: mailx tinyca The following NEW packages will be installed: libevent-core-2.1-6 mysql-server mysql-server-5.7 mysql-server-core-5.7 0 upgraded, 4 newly installed, 0 to remove and 0 not upgraded. Need to get 0 B/10.5 MB of archives. After this operation, 92.9 MB of additional disk space will be used. Do you want to continue? [Y/n] Y Preconfiguring packages ... Selecting previously unselected package mysql-server-core-5.7. (Reading database ... 193811 files and directories currently installed.) Preparing to unpack .../mysql-server-core-5.7_5.7.29-0ubuntu0.18.04.1_amd64.deb ... Unpacking mysql-server-core-5.7 (5.7.29-0ubuntu0.18.04.1) ... Selecting previously unselected package libevent-core-2.1-6:amd64. Preparing to unpack .../libevent-core-2.1-6_2.1.8-stable-4build1_amd64.deb ... Unpacking libevent-core-2.1-6:amd64 (2.1.8-stable-4build1) ... Selecting previously unselected package mysql-server-5.7. Preparing to unpack .../mysql-server-5.7_5.7.29-0ubuntu0.18.04.1_amd64.deb ... Unpacking mysql-server-5.7 (5.7.29-0ubuntu0.18.04.1) ... Selecting previously unselected package mysql-server. Preparing to unpack .../mysql-server_5.7.29-0ubuntu0.18.04.1_all.deb Unpacking mysql-server (5.7.29-0ubuntu0.18.04.1) ... Setting up libevent-core-2.1-6:amd64 (2.1.8-stable-4build1) ... Setting up mysql-server-core-5.7 (5.7.29-0ubuntu0.18.04.1) ... Setting up mysql-server-5.7 (5.7.29-0ubuntu0.18.04.1) ... /var/lib/dpkg/info/mysql-server-5.7.postinst: line 191: /usr/share/mysql-common/configure-symlinks: No such file or directory dpkg: error processing package mysql-server-5.7 (--configure): installed mysql-server-5.7 package post-installation script subprocess returned error exit status 127 dpkg: dependency problems prevent configuration of mysql-server: mysql-server depends on mysql-server-5.7; however: Package mysql-server-5.7 is not configured yet. dpkg: error processing package mysql-server (--configure): dependency problems - leaving unconfigured No apport report written because the error message indicates its a followup error from a previous failure. Processing triggers for libc-bin (2.27-3ubuntu1) ... Processing triggers for systemd (237-3ubuntu10.39) ... Processing triggers for man-db (2.8.3-2ubuntu0.1) ... Processing triggers for ureadahead (0.100.0-21) ... Errors were encountered while processing: mysql-server-5.7 mysql-server E: Sub-process /usr/bin/dpkg returned an error code (1) I tried removing and installing again but it showed the same error I followed the these steps too but was of no use sudo dpkg --configure mysql-server-5.7 and also tried sudo apt-get upgrade. | I have a website server on Ubuntu server 18.04 with apache and mysql. The database stopped for no apparent reason. I just did a restart of mysql server to solve the issue but after a simple update I got some errors on mysql-server package. The update was for other packages and not mysql-server package. Mysql still stops at least once a week and each time I have to restarts the mysql-server. Can some one help me to understand the error please ? Here the result of: dpkg --configure -a Configure mysql-server-5.7 (5.7.23-0ubuntu0.18.04.1) ... /var/lib/dpkg/info/mysql-server-5.7.postinst: ligne 191: /usr/share/mysql-common/configure-symlinks: no file or folder dpkg: erreur de traitement du paquet mysql-server-5.7 (--configure) : installed mysql-server-5.7 package post-installation script subprocess returned error exit status 127 |
I have a long list I would like to break into shorter lists. I am using a list comprehension but it seems a bit long and inelegant. Is there a better way? # z is a list z = range(99) ## zz should slice z into short lists with three members ## using list comprehension I get this zz = [ z[i : i+3] for i,x in enumerate(z) if i%3 == 0 ] # seems a bit verbose. is there a cleaner way? | I have a list of arbitrary length, and I need to split it up into equal size chunks and operate on it. There are some obvious ways to do this, like keeping a counter and two lists, and when the second list fills up, add it to the first list and empty the second list for the next round of data, but this is potentially extremely expensive. I was wondering if anyone had a good solution to this for lists of any length, e.g. using generators. I was looking for something useful in itertools but I couldn't find anything obviously useful. Might've missed it, though. Related question: |
Before I go and pay is there a free source for UK Postcode Boundaries, ideally down to Postcode Sector level ("AA00 0" or even better "AA00 0A")? | I am trying to find the shapefiles for postcode sector and districts in the UK. Specifically inside London. I know I can go and pay for these but I only really need to use them once. I want to generate my own mapping tiles with the shapes on one version of the tiles. Allowing me to show all the postcode boundaries without overloading the JavaScript on the client side. I could "redraw" some of shapes myself (tracing from others) but would be great if there were some shapefiles already out there. Can anyone help? |
I did the Three-Way ANOVA test and A, B, C, AB, B*C, A*C, A*B*C are all significant. Now, What can I tell based on this results? Is it valid to say for example A*B is significant? Or the fact that A*B*C is significant, makes it wrong to say A*B is significant? Should/Can I do Two-way ANOVA even though I have 3 factors? | I have a significant three-way interaction (with no significant two-way interactions and no significant main effects). To begin with I have followed this up with two two-way ANOVAs (one at each level of the third variable). The first part of my question is whether this is an appropriate follow-up. This showed no significant main effects or interactions at either level of the third variable...is this the end of the analysis? If so, how would I interpret the three-way interaction? |
I am unable to delete files from my computer.Whenever I try to delete it, the following message appears : "THE FILE NAME YOU SPECIFIED IS NOT VALID OR TOO LONG". Is there any other method to delete that file other than booting into Linux Live Disc and mounting the Windows drive and deleting it through Linux? | My wife has several files and folders that somehow ended up having filenames that have caused them to be undeleteable (can't be deleted) by normal means or via the command line. I believe the filenames are too long due to the depth of the folder structures. Does anyone know of a good utility for cleaning up files like this? |
What is needed -by definition- to determine the shortest (Euclidean) distance between two parallel lines in the x,y plane? I am thinking if someone can write this down (mathematically) beautifully covering both knowing the equations of the lines or the coordinates of two points lying on the lines. | Suppose there are two parallel lines: $w_1x_1+w_2x_2=c_1$ (Line 1) and $w_1x_1+w_2x_2=c_2$ (Line 2). What is the distance between them (the shortest distance between any two points)? I know the answer is $d=\frac{|c_1-c_2|}{||w||}$ where $||w||=\sqrt{w_1^2+w_2^2}$. The method I was going to calculate is as follows: 1) find any point on Line 1 $(x_1^0,x_2^0)$ such that $w_1x_1^0+w_2x_2^0=c_1$ 2) calculate the perpendicular line (Line 3) to Line 1 and passing through $(x_1^0,x_2^0)$ 3) find the point $(x_1^1,x_2^1)$ where Line 3 intersects Line 2 4) calculate the distance between $(x_1^0,x_2^0)$ and $(x_1^1,x_2^1)$ However I couldn't figure out the algebra of this method. Can someone show me the steps of the above calculation? Or is there any simpler way to calculate this? Thanks. |
My php Web application not supporting Arabic language. I want to add data from a form and display the table in browser. When I type Arabic letters it store some other characters(أخبار أخباØ) and display as ????? in browser. But the same application support Arabic in my local server localhost. How to solve this please help. | I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1. Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur? This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2. |
I've been trying for hours to make these images appear on top of each other. I've tried using position and z-index but I can't make it work.Please help. CSS/HTML. HTML. <div class="test"> <img class="bg" src="images/pattern-bg.svg" alt=""> <img class="img" src="images\image-tanya.jpg" alt="tanya"> </div> CSS ````````````````````````````````````````````````````````````````` .bg { position: relative; height: 450px; width: 450px; margin: 0; } img { position: relative; float: right; height: 350px; width: 350px; } `````````````````````````````````````````````````````````````````` Thank You. | I want to overlay one image with another using CSS. An example of this is the first image (the background if you like) will be a thumbnail link of a product, with the link opening a lightbox / popup showing a larger version of the image. On top of this linked image I would like an image of a magnifying glass, to show people that the image can be clicked to enlarge it (apparently this isn't obvious without the magnifying glass). |
for academic purposes I'm doing a very specific task where i need to calculate the Cell Constant of an American Non-Polarized Plug, ie, without same length the prongs. So I need to know what are the dimensions of it, namely, length, thickness,wide and distance between the probes. I cannot get the dimensions for this plugs anywhere on the internet , only from polarized ones, so if any kind soul with one at home could give I would be very appreciated. Thank you. | I am trying to find the dimensional tolerance on US electrical plugs. I have tried looking online, but I have only been able to find that they are called , and have found the picture below showing length and height for the male connector (but not width of the male prong), and I haven't been able to find dimensional tolerances anywhere. I ask here because I'm assuming there's a US code that governs electrical plugs, but I can't seem to find the standard anywhere. |
I was having a discussion with a stubborn person I know over which of these two forms was more semantically correct, although there is no logical difference to the code: 1. for(int x = 0; x < 10; x++) // do something 2. for(int x = 0; x < 10; ++x) // do something Is it better to pre-increment or post-increment in a for loop? | Is there a difference in ++i and i++ in a for loop? Is it simply a syntax thing? |
I was working on creating a container class for a JTextField object, but I keep running into trouble whenever I try to get the text in the text field. class myTextField{ String defaultText; String currentText = ""; JTextField field; int xPos; int yPos; int xSize; int ySize; myTextField(JFrame frame, String newDefaultText, int newXPos, int newYPos, int newXSize, int newYSize){ defaultText = newDefaultText; xPos = newXPos; yPos = newYPos; xSize = newXSize; ySize = newYSize; JTextField label = new JTextField(defaultText); frame.add(label); label.setBounds(xPos, yPos, xSize, ySize); } public void setText(String text) { this.currentText = field.getText(); if(text == "") { this.currentText = this.defaultText; } this.currentText = text; } public String getText() { System.out.println(field.getText()); this.currentText = field.getText(); return this.currentText; } } Whenever I use the getText() function of this class, it gives me this error: Exception in thread "main" java.lang.NullPointerException at Examples.myTextField.getText(Example_312.java:182) at Examples.Example_312.updateFrame(Example_312.java:81) at Examples.Example_312.main(Example_312.java:49) Unfortunately, that error isn't very descriptive, and so I'm having trouble finding what's going wrong in my code. I know it's failing when I call "field.getText();", but I don't know why. If someone could explain it to me, or offer a solution, I'd really appreciate it! | What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them? What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely? |
So I created two files, each with 127,955 lines and 24 random characters per line. As far as text the two files were completely identical. However one file had Unix line breaks and the other had Windows line breaks. The file with Unix line breaks was 3,124 KB, while the file with Windows line breaks was 3,249 KB. There were no other differences between the files so I have to assume that for some reason Windows line breaks take up more space. Any idea why? | Just out of curiousity.. Why are the line endings different for Windows and Unix. I was looking around for the answer but not found. |
Give $C^1([a,b])$ the sup metric induced from $(C^0([a,b]),||.||)$. I want to know if $C^1([a,b])$ is complete. My thinking is to show that $C^1([a,b])$ is a closed subset of $C^0([a,b])$. Let $(f_n)$ be a sequence of $C^1([a,b])$ functions where $f_n\to f$ (sup-norm convergence). Since differentiability implies continuity, $(f_n)\in C^0([a,b])$, where sup convergence is the same as uniform convergence. The sequence $(f'_n)$ is also in $C^0([a,b])$. I know that If $f_n$ is a sequence of differentiable functions with $f_n\to f$ uniformly and $f'_n\to g$ uniformly, then $f$ is differentiable and $f=g$. So if $(f'_n)$ converges, it converges to $f'$. Since $(f'_n)\in C^0([a,b])$, $f'\in C^0([a,b])$, so $f\in C^1([a,b])$. So if I can show $f'_n$ converges in $C^0[a,b]$, then $C^1([a,b])$ is closed and the proof is done. But this only works if must $(f'_n)$ converge. Is this true, and if so why? | The space $ C^1[0,1] $- the space of all continuously differentiable functions on $ [0,1]$ is not a Banach space with respect to the sup norm,$ \|.\|_{\infty} $ since the uniform limit of a continuously differentiable function need not be differentiable. How can I illustate this statement using a counter example? Can I use $ f_{n}=\frac1 n \sin nx $ as a counter example? Also, is $ C^1[0,1] $ is same as the space given by $ X=\{f\in C^1[0,1]:f(0)=0 \}$. Can I use the same example to show that this is not a Banach space? More help is appreciated! Thanks! |
I am a bachelor student in mathematics and studying group theory at home I came across this exercise where there is need to show the existence of this group, because given any prime, is it possible to ensure that there is a group of order $p^{3}$ ? | Can anyone helo me out with this question: "Prove that for each prime there exists a nonabelian group of order $p^3$". This is my attempt: I know how to show that $|Z(G)|= p$. So, since $C(x)$ contains $Z(G)$ for every $x$ not in $G$ then $|C(x)|> |Z(G)|$ i.e. $|C(x)|> p$. But $C(x)$ is always a subgroup of $G$ so it’s order must divide the order of $G$ and so $|C(x)= p^2$. (If $|C(x)|= p^3$ then $|G:C(x)|= |G|/|C(x)| = p^3/p^3 = 1$, so the number of elements in every conjugacy class would be 1, which would imply that every element is in the center of $G$, which in turn would mean that $G$ is abelian, which is not what we're after.) If $|C(x)|= p^2$ then $|G:C(x)|= |G|/|C(x)| = p^3/p^2= p$. Here’s where I don’t know how to go forward. I know that if there would be $p^2 – 1$ conjugacy classes then $|G |= |Z(G)|+ (p^2-1) \cdot|G:C(x)|= p + (p^2-1)p = p + p^3 – p = p^3$. But how do I know that there actually exists a group with exactly $p^2 – 1$ conjugacy classes? Greatful for input on my reasoning and also other ways of proving this, including how to construct such a group. |
I have seen many questions in Stack Overflow which are unanswered or answers that do not provide solutions. When I need a solution for something, I have been stuck because there's no solution there. Even when the answerer got many upvotes, and I decided to try the solution, they have mostly not worked. What exactly should the community do to unanswered or unsolved questions? Is there a specific community legally authorized by this site to review and answer such questions for others to get valid references? | I asked a question almost as soon as I got my account. I got a few decent answers, but none of them helped solve my problem. The question has long since become buried by newer questions, and there's still no accepted answer. Unfortunately, because there are quite a few answers with votes, to a casual observer it probably looks like the question was answered and I just neglected to mark an answer as accepted, and the system does not consider it "unanswered". Or, I asked a question that was a bit more difficult to answer. After waiting for some time, I received no answers, little or no comments, and only a few views. The question does show up in the "unanswered" list, but no one has answered my question. In either case, what's the protocol for me to try to get this question answered? I see several options: Post the question a second time, possibly linking to the original, to get attention for the original question. This is encouraged on sites like Reddit. However, it's probably not appropriate here, since we're encouraged to check for duplicates and not submit a question that's already been asked by someone else, so this probably falls under that heading. Wait for some kind of wiki-like talk page to be implemented, then post a plea on the talk page for input and hope that activity on the talk page bumps up the question. Edit the question, but do nothing further on the Stack Exchange site. If I edit my post to say that I haven't accepted any of the current answers but am looking for more, then the question might get answered eventually by people browsing through old questions to find something they can answer. Post the question on other sites, but link to my original question on Stack Exchange. People will either answer here, or they'll answer on the other site and I can post the accepted answer here myself. This might be considered spamming, so it might be better to do this without the link. For more information, see the "" page in the . |
Sorry for posting like this but I am learning I want all the results to have a hr or any html based line except the last one I put a line break but it won't look good help me foreach ($newsqry->result() as $n) { $nr=$n->numrows(); $nlink = array_keys($routesAll, "news/index/" . $n->n_id); ?> <div class="row"> <div class="col-md-6 imgpost"> <a class="post-imgn" href="<?=site_url($nlink)?>"> <img class=""src="<?=base_url("assets/uploads/news/thmb/$n->img")?>"alt="<?=character_limiter($n->title,'50')?>"> </a> </div> <div class="col-md-6 descpost"> <div class="post-category com" > <?php $t = $n->tags; $s = explode(',', $t); foreach ($s as $a) { ?> <a class="tags" href="<?=site_url("news/view?tag=".strtolower(str_replace(' ','-',$a)))?>"><?=ucwords($a)?></a> <?php } ?> </div> <h3 class="post-title news"> <a href="<?=site_url($nlink)?>"><?=character_limiter($n->title,'100')?>"</a> </h3> <ul class="post-meta"> <li><a href="<?=site_url("news/view?author=".strtolower(str_replace(' ','-',$n->author)))?>"><?=$n->author?></a></li> <li><i class="fa fa-clock-o" aria-hidden="true"></i> <?=date("h:i A",strtotime($n->time))?> <?=date("F-d-y",strtotime($n->date))?></li> </ul> <p class="descfornews"><?=character_limiter(strip_tags($n->desc),'190')?></p> </div> </div> <?php if($nr<1){echo "<hr>";}else{ echo "<h3>End of Page</h3>";}?> <?php } ?> | I am writing a SQL query creator using some parameters. In Java, it's very easy to detect the last element of an array from inside the for loop by just checking the current array position with the array length. for(int i=0; i< arr.length;i++){ boolean isLastElem = i== (arr.length -1) ? true : false; } In PHP they have non-integer indexes to access arrays. So you must iterate over an array using a foreach loop. This becomes problematic when you need to take some decision (in my case to append or/and parameter while building query). I am sure there must be some standard way of doing this. How do you solve this in PHP? |
The three dimensional torus (the periodic domain in Navier-Stokes equations $\mathbb{T}^3=(\mathbb{R}/\mathbb{Z})^3$) is compact. Can anyone here give us a detailed proof. | I am having difficuties in showing a torus is compact. Initially I wanted to use Heine-Borel theorem, but after that I realise we are not working in $\mathbb{R}^n$ space. So a simple way to show torus is compact is by definition. But after defining an open cover for torus, I don't know how to proceed. Can anyone guide me? |
My first Ubuntu installation was 12.04 LTS about a month ago on the desktop PC detailed below. This worked well but I forgot that if it works don't try to fix it and I upgraded to 14.04 LTS. Unfortunately this gives frequent ...Internal Error ... messages and occasionally freezes. I was learning to live with these hiccups but the latest problem is that the graphics have some how degraded to looking quite "chunky" and movement of windows around the screen is very slow. My preferred solution for now would be to revert back from 14.04LTS to 12.04LTS. Is this possible? System details: Processor: Intel® Core™2 Quad CPU Q6600 @ 2.40GHz × 4 Graphics: VESA: G86 Board - p403h10 Monitor: Flatron L225WS Many thanks, Arnie | I just installed a new version of Ubuntu and I want to roll it back to the previous version. How can I do that? Is that even possible? |
Occasionally some processes on my GNU/Linux desktop (such as gv and gnash) use up the physical memory and cause thrashing. Since these processes aren't important, I want them to be automatically killed if they use too much memory. I think the /etc/security/limits.conf file and the -v option could be used for this. The question is whether it limits the amount of available memory per process of a particular user, or the sum for all the processes of a user. Also I would like to ask how to make change to that file in effect without rebooting. | I'm running pdftoppm to convert a user-provided PDF into a 300DPI image. This works great, except if the user provides an PDF with a very large page size. pdftoppm will allocate enough memory to hold a 300DPI image of that size in memory, which for a 100 inch square page is 100*300 * 100*300 * 4 bytes per pixel = 3.5GB. A malicious user could just give me a silly-large PDF and cause all kinds of problems. So what I'd like to do is put some kind of hard limit on memory usage for a child process I'm about to run--just have the process die if it tries to allocate more than, say, 500MB of memory. Is that possible? I don't think ulimit can be used for this, but is there a one-process equivalent? |
"I touched their forehead[s] with my fingertip." I'm not certaint whether or not forehead in this example should be singular or plural. There's a group of people, so obviously, multiple foreheads are being touched. However each individual person only has one forehead. | After the therapy, eight children (43%) became able to crawl/move on their back. Or should I use "on their backs"? Singular because each child only has one back, or plural because we're dealing with eight backs? |
I have a custom block type that only has one field: an entity reference to my news content type. I am trying to display two specific fields from the news content type but can't figure it out. This entity reference field has a machine name of field_featured_news I have created a file with the filename block--block-content-testnews.html.twig In this file, I can use {{ content }} and it will render the full entity (based on the settings in Manage Display. However, I can't access the image field that is within the news content type. The field's machine name is called field_featured_news_image. I have tried adding the following to no avail: {{ content.field_featured_news_image }} {{ content.field_featured_news_image.0 }} {{ content.field_featured_news_image.entity.uri.value }} and many others. Only {{ content }} will display anything but it's the entire news node. | In Drupal 8, I have a content type, that has an "entity_reference" field and I wish to access the referenced node's fields in twig template. the kint() output for the field is: In this list I can't find the referenced node's field values. How can I (if at all possible) load the node or node fields/values in twig? Best, Alari |
I have a couple of gamer profiles that aren't used anymore but I can't find out how to delete them. | I can't figure out how to delete gamer profiles off my Xbox 360. I have a few profiles that were duplicates and some that aren't used. Is it possible to delete them? |
I am using the plugin zonal statistics to calculate the sum of the raster cells within polygons. How does this plugin handle pixels that are on the border of the polygon, are those cell values included in the statistics? I am using QGIS 1.8.0. | There are a couple Stackexchange posts asking this question, but neither of them were sufficiently answered: I am writing Python scripts that perform essentially the same operations as Zonal Stats, and I have been using Zonal Stats to check my scripts' outputs. I have noticed that when there are many cells in the polygon being queried, my results match perfectly, but there are discrepancies when there are only a few raster cells in the polygon. The following is an example of this. I am computing "count" for each polygon. Exhibit 1: The returned count is 0.45, which looks roughly correct if pixels can be treated fractionally rather than simply in/out. Exhibit 2: Similar result; count is 0.39. Exhibit 3: With a larger poylgon, now we see the count is exactly 2. Note that there are exactly 2 pixel centers contained in the polygon. Exhibit 4: Here, only one pixel center is within the polygon. The count is 1.008, though. If you exclude the polygon area from the pixel whose center is in the polygon, the remaining area is obviously greater than 0.008 of a pixel. From these exhibits, it seems that Zonal Statistics treats these cases specially. It looks like to me that if there are less than 2 pixel centers within the polygon, it performs some kind of averaging such as polygon_area/raster_cell_area to return the count. I should note that I have 48 of these polygons, and all returned counts greater than or equal to 2 are integers; fractional counts are only returned for <2. How are these fractional-pixel counts incorporated into the other statistics output by Zonal Stats? indicates strange behavior with max/min when using large raster cells, and my own testing returns mean values not congruous with simple "pixel center in/out of the polygon." To reiterate, I get exact agreement when the underlying raster contains many pixels within the polygon. I couldn't find any documentation about this, and it may be important when people have never had problems with Zonal Stats but use a coarse raster and remain unaware that there is a different behavior when there are only a few pixels within the polygon. |
Why has this question become hot twice within a few seconds of interval? Is that expected to see this in the question log? | The Boardgames Stack Exchange question became a Hot Network Question three times, according to its : All three events have the exact timestamp (19:14:39 UTC - shown when you click the 'toggle format' link or upon hovering) so it's probably a race condition or something. It's not a unique case; finds instances on a single site, and lists all occurrences in the network (currently 448). The current record holders, with 44 HNQ entry events, are on Retrocomputing on Worldbuilding |
Someone who likes to taste everything, like food and drink. But I don't mean a glutton | Does such a word exist? I don't mean to excess (IE, a glutton), but rather one who eats because he enjoys eating. Essentially, I'm looking for a word that's synonymous with "a food hedonist", or "a hedonistic eater." A word would be ideal, but a term would suffice as well :). I love to eat! |
If a class has these two methods: public static synchronized void m1() {} public synchronized void m2() {} Can two threads execute these two methods at the same time? | The Java documentation says: It is not possible for two invocations of synchronized methods on the same object to interleave. What does this mean for a static method? Since a static method has no associated object, will the synchronized keyword lock on the class, instead of the object? |
Right now I have one (1) reputation and I need 20 to be in a chat. How do I test the chat API? Do I need to get more upvotes to chat or is there a "sandbox" chat that does not need rep? I know that the chat API is not formal and official and that is why I need to test it. If there isn't a chat sandbox that doesn't require 20 rep, I will accept an answer saying so. | I recently found this with the chatbot and wanted to know what all of the chatbot commands do (including learned ones and the ones with no definition.) What exactly was the Chat Sandbox designed for, and what are the commands/what do they do? |
I've been trying my hand at sourdough bread for a few months now and it is getting better and better, but this keeps happening, and I have no idea what might be the cause: My impression is that during the rise, the crumb tears into two pieces in the middle. This is probably relevant: The dough is 80% hydration white bread flour, around 3 hours autolysis, then lamination and three stretches and folds spaced out. Altogether around six hours of bulk fermentation, overnight in the fridge (5 °C), and baked in the morning on a pizza stone, with 250 °C with steam for 20 minutes and 220 °C for 20 minutes (the oven has the air convection turned on). My problem is I have no idea which part of the recipe is to blame for the outcome, so I'm not even sure where I am deviating from the recipe I'm trying to copy (to be very exact, I'm trying to follow this one now: ) I'm not sure if this is important, but it also doesn't open up so well (but I don't have a proper lame, so I'm struggling with the scoring): | The last couple of loaves I have made have had large air-bubbles which form at the top of the loaf, separating the crust in places from the crumb. Before shaping, I have been degassing my dough using the King Arthur Flour recommended technique of folding the dough over itself a few times. To shape, I form a rough rectangle, then fold the lower side to the middle and seal it shut with my fingers. I do this a couple more times until I have a nice loaf shape. Is it possible that I am over-proofing the dough before putting it in the oven? Or is it my shaping technique? |
I was thinking about creating a wizard character. Reviewing the spellcasting rules, I saw this: Most spells that require attack rolls involve ranged attacks. Remember that you have disadvantage on a ranged attack roll if you are within 5 feet of a hostile creature that can see you and that isn't incapacitated (see chapter 9). There are a lot of occasions that might arise that would make this a problem, or at least a bit of a hindrance. So as a D&D player normally would when they wanted to break a rule without actually cheating, I went to a list of feats and found Crossbow Expert: Thanks to extensive practice with the crossbow, you gain the following benefits: You ignore the loading quality of crossbows with which you are proficient. Being within 5 feet of a hostile creature doesn't impose disadvantage on your ranged attack rolls. When you use the Attack action and attack with a one handed weapon, you can use a bonus action to attack with a hand crossbow you are holding. I may be (am) overthinking things, but does this apply to magic attacks, such as cantrips like Eldritch Blast or Fire Bolt? The literal meaning of the feat says that I can, but it could also imply by the title and also the effects of the feat that this only applies to crossbows, or any other ranged weapon, excluding magic. The strongest evidence that it might not affect ability with ranged magic attacks is: Thanks to extensive practice with the crossbow With a crossbow, not with magic. | The Crossbow Expert feat gives three benefits, the first of which is explicitly tied to crossbows and the last of which to only hand crossbows. But in the middle, there is: Being within 5 feet of a hostile creature doesn't impose disadvantage on your ranged attack rolls Notably missing is a qualifier like "when attacking with a crossbow". Does this mean that the benefit applies to other ranged weapons and to spells which require ranged attack rolls? Or does the name of the feat itself limit this to crossbows? |
I have two Schengen visas one from Spain: valid until 05/19/2017 one from France: valid from 05/20/2017 until 11/19/2017 I am traveling Friday, 05/12/2017 to Spain for two days then flying to France for two weeks. Do you think I will run into issues because I have a back to back visas? | I currently have a valid multiple entry Schengen visa that expires on Feb 10th (issued by the Spanish consulate). I need to visit the Czech Republic from Feb 9th to Feb 15th. For this, I am getting a visa starting Feb 11th from the Czech consulate as I was advised that I cannot have two simultaneous visas. Is it possible for me to enter Czech republic on the current visa on Feb 9th, and stay past its expiry up to Feb 15th using the new visa without leaving the Czech Republic? Will there be any likely problem either while entering or exiting Schengen zone (I am entering Schengen in Frankfurt)? |
We are given that $f$ is analytic in a bounded domain $D$ and continuous on the boundary $\partial D$. Also we can assume that $|f(z)| \leq M$ for $z \in \partial D$ for $z \in \mathbb{C}$. I'm unsure what it means to be continuous on the boundary $\partial D$, but here is what I have thought up so far: Since $f$ is analytic in the bounded domain $D$ we have that $f$ is continuously differentiable at some point $z \in D$. Since $f$ is continuously differentiable at $z$ we have that $f'$ is also continuous at $z$. As $f$ is continuous on the boundary $\partial D$ we have by the definition of $\epsilon - \delta$ continuity that for every $\epsilon >0$ there exists a $\delta >0$ such that $|z-z_0|<\delta \implies |f(z)-f(z_0)|<\epsilon$. We are also allowed to assume that $|f(z)| \leq M$ for $z \in \partial D$ for $z \in \mathbb{C}$. I'm not sure where to head with this problem, or if I have set up what was given correctly. I think since $|f(z)-f(z_0)|<\epsilon$ we can rewrite this as $||f(z)|-|f(z_0)|| \leq \epsilon$ and so $|f(z)| \geq -\epsilon + |f(z_0)|$ where we then have that $M \geq -\epsilon +|f(z_0)|$. But, I don't think this leads in any particular direction. | Suppose that $V$ is the bounded open subset of the plane and $f\in C(\bar V)\cap H(V)$. Show that if $M\ge 0$ and $|f(z)|\le M$ for all $z\in\partial V$ then $|f(z)|\le M$ for all $z\in V$. I was trying to apply maximum modulus principle or open mapping theorem but the open set $V$ is not given to be connected and since then i have no idea how to do it. Any type of help wil be appreciated. Thanks in advance. |
Consider the eigenvalue equation: $$\hat{Q}\Psi = q\Psi$$ where $q$ and $\Psi$ are eigenvalues and eigenfunctions of the hermitian operator $\hat{Q}$. If the spectrum of the hermitian operator is discrete, then the eigenfunctions lie in the Hilbert Space and constitute physically realizable states. Why do discrete eigenvalues imply that their associated eigenfunctions are square-integrable (and hence live in the Hilbert Space)? | These facts are taken for granted in a QM text I read. The purportedly guaranteed non-normalizability of eigenfunctions which correspond to a continuous eigenvalue spectrum is only partly justified by the author, who merely states that the non-normalizability is linked to the fact that such eigenfunctions do not tend to zero at infinity. Not a very satisfying answer. What I'm really after is an explanation based in functional analysis. I believe there is a generalized result about inner products being finite for discrete spectra but infinite for continuous spectra. Can anyone shed some light on this? |
I'm trying to install reaver-1.4 in my Ubuntu 18.04 system, but it shows this error: root@rashedul-ubuntu:~/Desktop/reaver-1.4/src# ./configure checking for gcc... no checking for cc... no checking for cl.exe... no configure: error: in `/home/rashedul/Desktop/reaver-1.4/src': configure: error: no acceptable C compiler found in $PATH See `config.log' for more details. How can I fix this? | I am trying to install reaver 1.4, but when I run ./configure ; make I get this message at the end int ret_val = EXIT_FAILURE, r = 0; I have searched a fair bit and cannot find an answer, any help would be appreciated. I apologize if this has been answered and I've just failed to find it. |
I tried to execute the command gpedit.msc through the "run program" window, but when i do it i get an error that says the command doesn't exist. I tried to execute the command from the administrator user. My pc has windows 10 Home premium x64 | I want to make some changes to Windows that require using the Group Policy Editor (gpedit.msc). Unfortunately the Group Policy Editor is not included with the Starter Edition, Home and Home Premium editions of Windows. How can I install it? |
i have a modal form displaying a table created by calling a php form function search() { xmlhttp= new XMLHttpRequest(); xmlhttp.open("GET","searchitem.php?id="+document.getElementById("stext").value,false); xmlhttp.send(null); document.getElementById("d1").innerHTML=xmlhttp.responseText; document.getElementById("d1").style.visibility='visible'; } searchitem.php creates table from the searched value. i want to click BUTTON in a row to select the values. <script> var table = document.getElementById('sTable'); for(var i = 1; i < table.rows.length; i++) { table.rows[i].onclick = function() { //rIndex = this.rowIndex; document.getElementById("sitemno").value = this.cells[0].innerHTML; document.getElementById("sdesc").value = this.cells[1].innerHTML; }; } </script> | I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off. This happens on page ready and works just fine. The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound. I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option. |
Could we get comment username completion in the SE app? It's extremely handy with some of the longer usernames on the desktop site. | When commenting, having an autocomplete when you want to @reply to a user would be wonderful (similar to the one available on the desktop site). Normally when I'm on mobile site, I can copy/paste the username, remove the spaces, and I move on with life. But without copy/paste available within the app, the complex or unicode names are nearly impossible to use @reply. |
I know that textbooks state that when conducting level-log regression, I should generally divide the estimated coefficient by Beta / 100 for a percentage point interpretation. For example, a 1 % increase in X leads to a percentage point change in Y. However, when we have a linear probability model, where y={0,1}, is it still necessary to divide the estimated log(X) coefficient by 100 for the same percentage point interpretation as the one stated above? My intuitive answer is no, it is no longer necessary in the linear probability model case, but I am not quite sure if I am correct or why I am correct. Thank you in advance for your clarification. | If I have a level-log model, such as y= β0+β1log(x), I know the interpretation is "If we increase x by one percent, we expect y to increase by (β1/100) units of y." So, my questions are If y is a percentage variable, what is the correct interpretation of the resulting regression? Is it still the same but has a unit of percentage instead of unit, so the interpretation becomes "If we increase x by one percent, we expect y to increase by (β1/100) percent of y"? Or we don’t have to divide β1 by 100, so the interpretation becomes "If we increase x by one percent, we expect y to increase by β1 percent of y"? Can I convert my variables (ex: interest rate and inflation rate) to logarithm if it has a unit of percentage? If it can be done, can I change my model into log-log model, although my variable y has a unit of percentage, so the model becomes log(y)= β0+β1 log(x) ? What is the correct interpretation of this model? |
I know what trace is in matrix algebra, but does it have any intuitive physical significance when acted on a quantum mechanical operator? What aspect of an operator $A$ does ${\rm Tr}(A)$ capture? Or is it just a convenient mathematical tool and nothing more? | I was recently thinking what information do we get from a matrix. So if we say the columns (or rows) of a matrix define the basis of a system, say vectors of 3 dimensional space. Then the determinant will tell about the volume of the space enclosed by those vectors. Does trace give any information about the space? |
I am working on a huge database. I want to find all the tables in all the database which contains columns name say "xyz" (cann't say actual column name). Is there any query or other way to solve the my problem. TIA FYI DB : MySql | I have 2-3 different column names that I want to look up in the entire DB and list out all tables which have those columns. Any easy script? |
I have seen a situation where a great number of questions were being bumped to the top of the active queue as they were being edited by one person one after the other. The reason for the edits was to link multiple questions to relevant new tags and remove incorrect tags, which was a good idea to me, but the problem with doing this is the fact that this bumps the questions to the top of the 'active' queue which everyone lands on by default when arriving on the site. Therefore any new questions get pushed down the queue with the risk of being lost amongst the old questions. Should edits which are just tag edits result in the question having their active status changed? | While bumps are generally good, there are niche cases where they are harmful: I recently decided I would consolidate two tags on Stack Overflow: "openoffice" and "openoffice.org". They refer to precisely the same thing, and having two tags for them just fragments the organizational structure. However, after a couple of retags, I noticed that these questions were being bumped to the front page, clogging it up. Not wanting to be disruptive, I stopped retagging. This prevents a very useful organizational benefit of SO's community structure. As well as consolidating two identical tags, I could do things like look at each question in "openoffice.org", and add the tag "openoffice-writer", "openoffice-calc", etc. where appropriate. Abuse would be unlikely, due to the 500 reputation minimum for retagging questions. Update, July 2012: I think this problem is much less bothersome now that tags can have aliases. My original use-case was merging two tags, which is somewhat solved by aliases. |
I downloaded a mile marker geojson from the Idaho DOT and the CRS is listed as 102605, which doesn't seem to exist outside of the DOT office. This is the extent of the layer metadata: XMin: 2254295.3529000003 YMin: 1199867.0130000003 XMax: 2743212.4619000005 YMax: 1980420.2782000005 Spatial Reference: 102605 (102605) link to mapserver info: | Using Geoserver, I'm trying to get the correct projection for a map layer that is provided by the State of Idaho. I've tried looking up the EPSG code from . However, the search results throws an error. Here is the location of the data - Here are the results of the .prj file PROJCS["NAD_1983_Transverse_Mercator",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",2500000.0],PARAMETER["False_Northing",1200000.0],PARAMETER["Central_Meridian",-114.0],PARAMETER["Scale_Factor",0.9996],PARAMETER["Latitude_Of_Origin",42.0],UNIT["Meter",1.0]] I found this page that should help, but I don't know what it all means. |
I have a script that outputs a column of text. I want to prepend each entry in the column with a string stored as a variable. How can I do this? For example, consider the command $ echo -e "john\npaul\ngeorge\nringo" john paul george ringo Now, I'd like to prepend each entry in this column with the value of the environment variable $HOME. I've tried piping into awk like this: $ echo -e "john\npaul\ngeorge\nringo" | awk '{printf("%s%s\n", $HOME, $1)}' johnjohn paulpaul georgegeorge ringoringo This output is not what I'm looking for. What am I doing wrong? | Possible Duplicate: I have a script, in which a script snippet is x=3 awk '$2=$x{print $1}' infile the external variable is x, but it prompts an error in awk so in this situation,how to make awk run successfully? thanks! |
Hi, I am trying to install uget and I get this error message "This requires installing packages from unathenticated sources" and there are only two options. Ok and Repair, and even if i click both their is nothing happening. It keeps on popping up. I am using Ubuntu 14.04 64bit Please help. Thank you. | I tried installing VLC Player yesterday, and I got the Requires installation of untrusted packages error. I searched for hours for a solution to this problem, and finally came upon a suggestion that said to change servers for downloading updates from. I did this, and it gave me a 404 error when I clicked on "Check" in the Update Manager. I tried switching my server back to the main one (and after that, several other ones), but I am now still getting a 404 error: And the other error I get when downloading or updating: Edit: Output of cat /etc/apt/sources.list: deb-src http://us.archive.ubuntu.com/ubuntu/ precise main restricted #Added by software-properties # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to # newer versions of the distribution. deb http://us.archive.ubuntu.com/ubuntu/ precise main restricted multiverse deb-src http://us.archive.ubuntu.com/ubuntu/ precise multiverse universe #Added by software-properties ## Major bug fix updates produced after the final release of the ## distribution. deb http://us.archive.ubuntu.com/ubuntu/ precise-updates main restricted multiverse deb-src http://us.archive.ubuntu.com/ubuntu/ precise-updates restricted main multiverse universe #Added by software-properties ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team. Also, please note that software in universe WILL NOT receive any ## review or updates from the Ubuntu security team. deb http://us.archive.ubuntu.com/ubuntu/ precise universe deb http://us.archive.ubuntu.com/ubuntu/ precise-updates universe ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team, and may not be under a free licence. Please satisfy yourself as to ## your rights to use the software. Also, please note that software in ## multiverse WILL NOT receive any review or updates from the Ubuntu ## security team. ## N.B. software from this repository may not have been tested as ## extensively as that contained in the main release, although it includes ## newer versions of some applications which may provide useful features. ## Also, please note that software in backports WILL NOT receive any review ## or updates from the Ubuntu security team. deb http://us.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse deb-src http://us.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse #Added by software-properties deb http://us.archive.ubuntu.com/ubuntu/ precise-security main restricted multiverse deb-src http://us.archive.ubuntu.com/ubuntu/ precise-security restricted main multiverse universe #Added by software-properties deb http://us.archive.ubuntu.com/ubuntu/ precise-security universe ## Uncomment the following two lines to add software from Canonical's ## 'partner' repository. ## This software is not part of Ubuntu, but is offered by Canonical and the ## respective vendors as a service to Ubuntu users. deb http://archive.canonical.com/ubuntu precise partner deb-src http://archive.canonical.com/ubuntu precise partner ## This software is not part of Ubuntu, but is offered by third-party ## developers who want to ship their latest software. |
I just booted up and it was like this, everything is zoomed in, but only in Chrome. Even the menu's in chrome are huge. Is this normal? How can I bring this back to normal? Here is a picture. | Last night, I updated my version of Google Chrome from 43.0.2357.81-1 to 43.0.2357.124-1. The most visible change is that the UI elements are way too large. Here's a comparison with Chrome (top), Firefox (center) and my system fonts (bottom); only Chrome is wrong: This isn't a page zoom issue. Chrome thinks my zoom is at 100%. I can shrink the page elements by zooming out, but the UI is still too large. I can fix this by launching Chrome with the --force-device-scale-factor flag. However, this isn't really a great fix; I'd have to change my launcher shortcuts and any programs that launch Chrome (e.g., web servers that auto-launch a browser, like Racket's). Using this flag also causes Chrome to start with a very small window size. I checked in chrome://flags and didn't see anything interesting matching the grep for "scale." If relevant, my desktop environment is Cinnamon on Linux Mint 17.1 64-bit. My screen resolution is 1920×1080, on a normal 14-inch (157 dpi) display. |
Question: Show that the harmonic mean is less than or equal to the arithmetic mean, and also less than or equal to the geometric mean, with equality if and only if $a=b$ ; ie., show that $$\frac{a+b}{2} \geq \sqrt{ab} \geq \frac{2ab}{a+b}$$ My attempt, I've shown the first equality which is $$\frac{a+b}{2}-\frac{2ab}{a+b}=(a-b)^2\geq0$$ My first question, should I write $\frac{(a-b)^2}{2(a+b)}\geq0$ or just leave as $(a-b)^2\geq0$? For the second, $$\sqrt{ab}-\frac{2ab}{a+b}=\frac{\sqrt{ab}(a+b)-2ab}{a+b}$$ $$=\frac{a^{\frac{3}{2}} \sqrt{b}+\sqrt{a} b^{\frac{3}{2}}-2ab}{a+b}$$ $$=\frac{\sqrt{ab}(a+b-2\sqrt{ab})}{a+b}$$ I stuck at here. Can anyone explain to me how to solve this question Thanks in advance. **I found other similar questions being asked in this site. But my question includes harmonic which is not a duplicate. | $ m_{a} = \frac{1}{2} (a + b) $ $ m_{g} = \sqrt{ab} $ $ \frac{1}{m_{h}} = \frac{1}{2}(\frac{1}{a} + \frac{1}{b})$ Attempted Solution: I believe I have shown the first step, which is $ m_{a} \geq m_{g} $ but i'm stuck on showing $ m_{g} \geq m_{h} $ $ \frac{a + b}{2} > \sqrt{ab} $ $ (\frac{a + b}{2})^2 > (\sqrt{ab})^2 $ $\frac{a^2 + 2ab + b^2}{4} > ab$ $a^2 + 2ab + b^2 > 4ab $ $a^2 -2ab + b^2 > 0 $ $(a - b)^2 > 0 $ so if $a = b$ we have $(a -b)^2 \geq 0$ Therefore, $m_{a} \geq m_{g} $ Now, i'm not sure if that is correct or not, if not can you please guide me to the complete solution or if I am correct on this part, provide a solution for $m_{g} \geq m_{h} $ |
I want to call an object action to create/update a record from visualforce Page that is loaded in Lightning Experience within a Lightning I-frame. I tried the following but it gives error, what am I missing? <apex:commandButton value="Create Account" action="{!URLFOR($Action.Account.CreateAccount)}"/> | I have Visualforce Page which redirects to standard accounts edit page with prepoulated value for record Type. The record type is getting populated using URL hack. But since URL hacks dont work in lightning experience this functionality is not working and the record type is not populated. Is there any other workaround to redirect to a standard page with pre-poulated values in Lightning? |
Updated as original was unclear. I'm setting up postfix on a computer to work with my email's SMTP. I don't want to enter my credentials in plain text, especially when typing in public. Is it possible to make bash not show my input for a command or two? Example: I'm entering a series of commands and then I want to echo a username and password into a config file. I'd like to quickly go into a mode where my input isn't shown on screen, then easily leave that mode with ctl+c. | When I want to ask for a password in a bash script, I do that : read -s ...but when I run bash in POSIX mode, with sh, the -s option is rejected: $ read -s sh: 1: read: Illegal option -s How do I securely ask for an input with a POSIX-compliant command ? |
I noticed water dripping from my kitchen ceiling. I informed my parents about it and they decided the best thing to do was rip part of the ceiling off? I am very worried about this as I think it may contain asbestos like one of those popcorn ceilings. Thanks for reading. | School in South Korea removed asbestos over the past few weeks. Now I am all paranoid. Is this asbestos? Found these dime-sized chunks by my desk. Higher resolution images are available here: There should be 4 pics. If not clear enough let me know. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.