求xsin(2x)的不定积分
问题描述：
求xsin(2x)的不定积分
答
-1/2xcos(2x)+1/4sin(2x)
答
∫ xsin2x dx
= -(1/2)∫ xdcos2x
=-(1/2)xcos2x + (1/2)∫ cos2x dx
=-(1/2)xcos2x + (1/4) sin2x + C