Matrix

Printable View

• November 23rd 2012, 05:44 AM
Petrus
1 Attachment(s)
Matrix
Hello i got a problem!
ima decide a inverkar to this Matrix A=1 0 -1 1 an it says clue ima set B= x y z tand decide x,y,z,t, for B shall be inverse to A.( its 2x2 the first 2 number are the number on top and the last 2 is at bottom idk what u say on english

Its a 2x2 Matrix sorry for not writing it with latex and sorry for My bad english.
So i did A•B and get C= 1x 1y, -1x+z, -1y+1t
idk why i did not write as t insted of having one before byt hope u guys did understand and looking forward to se all help
• November 23rd 2012, 10:00 AM
chiro
Re: Matrix
Hey Petrus.

Do you just want to find the inverted matrix of A given what is written in the attachment?

If the answer is yes, here is the Octave output for this problem:

>> A = [1, 0; -1, 1]
A =

1 0
-1 1

>> inv(A)
ans =

1 0
1 1
• November 23rd 2012, 10:09 AM
Deveno
Re: Matrix
suppose we want to invert:

$A = \begin{bmatrix}1&0\\-1&1 \end{bmatrix}$

your clue says to set:

$B = \begin{bmatrix}x&y\\z&t \end{bmatrix}$.

so we calculate:

$AB = \begin{bmatrix} x&y\\z-x&t-y \end{bmatrix}$

if B is to be the inverse of A, we must have AB = I.

thus:

x = 1
y = 0
z - x = 0
t - y = 1

from z - 1 = 0, we get z = 1.
from t - 0 = 1, we get t = 1.

thus:

$A^{-1} = B = \begin{bmatrix}1&0\\1&1 \end{bmatrix}$
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 4, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8214613199234009, "perplexity": 2839.1156945598664}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-52/segments/1418802773061.155/warc/CC-MAIN-20141217075253-00130-ip-10-231-17-201.ec2.internal.warc.gz"}