sin(x+y)cosy-cos(x+y)siny求解释

分类: 作业答案 • 2022-04-20 22:33:36

问题描述：

答

两角差的正弦公式
sin(x+y)cosy-cos(x+y)siny
=sin(x+y-y)
=sinx

答

sin(x+y)cosy-cos(x+y)siny
=sin[(x+y)-y]
=sin[x+y-y]
=sinx