# Homework Help: Problem with Integrals

1. Dec 6, 2009

1. The problem statement, all variables and given/known data

Ok, Im given a integral f(x) with a lower limit 0 zero and an upper limit of g(x). Its 1/(1+t^3)^(1/2)dt

g(x) is the integral from 0 to cosx of (1+sin(t^2))dt. I need to find f '(pi/2). Any suggestions on where to start? This is calc one. I can find g '(x) but I dont think thats what is require. I am not sure however on how to actually integrate it.

f '(x) would be 1/(1+(g(x))^3) but I Dont know what to do with g(x).

2. Relevant equations

find f'(pi/2)

3. The attempt at a solution

f '(x) would be 1/(1+(g(x))^3) but I Dont know what to do with g(x).

2. Dec 7, 2009

### clamtrox

Re: Integrals

Not quite right. Denote the integral as F(g(x)) - F(0). Now, differentiating this, you get F'(g(x)) * g'(x). When you get to dealing with g(x), remember that you only need to evaluate it in a single point; this should make things a bit easier.