Question

I'd love some help with this: Find the integral of sqrt(1+cos^2(x))dx
I've tried the substition cosx=icosu, and using the exponential form of cosx, nothing promising though. Any insights?

Answer 1

Here's Wolfram's answer:

http://www.wolframalpha.com/input/?i=integral%28sqrt%281%2Bcos^2x%29%29

I think this integral must be at a very high level, because I was unable to understand much of this.