∫x^2/(1+^2)dx,∫sin^2xdx计算不定积分
问题描述：
∫x^2/(1+^2)dx,∫sin^2xdx计算不定积分
答
∫ x^2/(1+x^2)dx
= ∫ (1 - 1/(1+x^2))dx
= x - arctan(x) + C
∫ sin^2xdx
= 1/2 ∫ (1 - cos(2x))dx
= 1/2 (x - 1/2 sin(2x)) + C