Originally Posted by

**rhickman** Two questions

Find the derivative of f(x)=$\displaystyle \sqrt{2x}$

I got the derivative $\displaystyle 1\frac2\sqrt2x$

Just confirming that's correct? I have to use the first principle rule to find it.

Second question is find the derivative of f(x) = $\displaystyle \frac{\4}{x+1}$

I believe the derivative should be $\displaystyle \frac{-\-4}{(x+1)^2}$

But when I work through the question (which I dont understand how to work through very well, because the example I was shown involved a 1 in the numerator not a 4)

I end up at $\displaystyle \frac{\1}{(x+1)^2}$

I'm not strong enough in latex to list these steps properly I dont think...

$\displaystyle \frac{\4}{x+h+1}-\frac{\4}{x+1}$

All of that, over h since the first principle is $\displaystyle \frac{f(x+h)-f(x)}{h}$

I dont know how to simplify any farther correctly (or get a 3 tier fraction on LaTex), I've tried following along with my example I was shown but it doesn't work correctly I dont think.

Any input is greatly appreciated, hopefully the LaTex helps to make my equations and stuff more clear.