∫cos^2(wt+φ)dt
问题描述：
∫cos^2(wt+φ)dt
答
∫cos^2(wt+φ)dt=∫(cos(2wt+2φ)+1)/2dt
=t/2+1/2*∫cos(2wt+2φ)dt
=t/2+1/(4w)sin(2wt+2φ)+C,C为任意常数.