化简: sinx cosx cos2x =? 需要详细过程,谢谢
问题描述:
化简: sinx cosx cos2x =? 需要详细过程,谢谢
答
sinxcosxcos2x
=(1/2)sin2xcos2x
=(1/4)sin4x
答
sinxcosxcos2x=(sinxcosx)*cos2x=1/2sin2x*cos2x=1/4sin4x
答
sinx cosx cos2x
=0.5(2sinxcosx)cos2x
=0.5(sin2xcos2x)
=0.5×0.5sin4x
=(1/4)×sin4x