1. The problem statement, all variables and given/known data Find the area of the surface obtained by rotating the curve about the x-axis: y=cos 2x, 0<=x<=pi/6 2. Relevant equations Surface area about the x-axis = Integral of 2pi * f(x) * sqrt(1+[f'(x)]^2) dx 3. The attempt at a solution I think I set up my integral correctly, so my problem is figuring out how to solve the integral. I have: 2pi * Integral of cos 2x * sqrt(1+4sin^2 2x) dx on [0, pi/6] I can't figure out how to solve that. And can someone teach me how to use Latex for integrals so it looks better.