Find the antiderivative: ∫[(3x+1)/cos^2(3x^2+2x)]dx
The Attempt at a Solution
I attempted to use "u substitution" but got stuck towards the end:
After my substitutions it looks like this:
∫(du)/2cos^2(u) = 1/2∫(du)/cos^2(u)
What do I do with the cos^2?
Thanks for any help that can be given