I was given the point P (4,2) and Q $(x,\sqrt{x})$ and was told to find the secant line. I forgot what the difference between secant and tangent was but I thought it might have something to do with that formula I was suppose to memorize but forgot. As far as I could make sense of this the formula should be something like $\frac{(a-h)+a}{h}$ so I used that and I got 1 which I think is wrong so I wrote 2. I was then given points like 3.5 3.9 3.99 and such and told to find the tangent lines I think and then estimate the tangent I think. I didn't know how to do this because I got -1 and 1 which can't be right so I made up numbers getting closer to two. I was then told to estimate the secant lines and I guessed 2 because I don't know how to do that.

I tried to take the derivative of it which gave me $\frac{1}{2}x^\frac{-3}{4}$ which gave me .56 something or so so I just made up an answer and guessed 2 because 4/2=2.