Hi

The goal is the find f'(x) if

f(x) = Integral sign (a= sec x; b= x^2) (1 + 2u^2)^ (1/2) <- that is the square root of (1 + 2u^2)

Hopefully that makes sense in how I am communicating the question.

So I started with letting t= sec x so dx/dt = sec x tan x and I am thinking I need to do the same with the x^2 but I don't know if it should be a different letter and then what do I do???

Any help or direction you can offer is greatly appreciated.

This calculus beginner