求∫xsin2xdx的不定积分
问题描述:
求∫xsin2xdx的不定积分
答
∫xsin2xdx
=1/2∫xsin2xd2x
=-1/2∫xdcos2x
=-1/2xcos2x+1/2∫cos2xdx
=-1/2xcos2x+1/4∫cos2xd2x
=-1/2xcos2x+1/4cos2x+C