Which substitution would be most effective for evaluating ∫sinx1+cos2xdx\int \frac{\sin x}{1+\cos^2 x} dx∫1+cos2xsinxdx?
u=sinxu = \sin xu=sinx
u=cosxu = \cos xu=cosx
u=1+cos2xu = 1+\cos^2 xu=1+cos2x
u=tanxu = \tan xu=tanx