Argh I had a picture for this but dont have enough reputation for anything on here. did it as I don't understand how to insert the maths notation in here.
If $f(x) = \int_0^{g(x)}(1+t^3)^{-1/2} dt$ where $g(x) = \int_0^{\cos x}(1+\sin (t^2)) dt$
I have to find $f'(\pi/2)$
I know it has something to do with substitution and I've tried integrating by parts and things like that too but its not working out. I think theres something about the way that the questions been asked thats not helping anyway thats the first question.
there'll be more in the future im sure.