求不定积分:∫xsin2xdx=
问题描述:
求不定积分:∫xsin2xdx=
答
∫xsin2xdx
=(-1/2)∫xdcos2x
=(-1/2)(xcos2x-∫cos2xdx)
=(-1/2)(xcos2x-(1/2)sin2x)+C
=(1/4)sin2x-(1/2)xcos2x+C