1. The problem statement, all variables and given/known data Evaluate the Integral: ∫sin2x dx/(1+cos2x) 2. Relevant equations 3. The attempt at a solution I first broke the numerator up: ∫2sinxcosx dx /(1+cos2x) 2∫sinxcosx dx /(1+cos2x) Then I let u = cosx so that du = -sinx dx -2∫u du/(1+u2) And now I'm stuck. I thought about turning 1+u2 into tan-1u + c, but I still have another u to deal with in the numerator.