化简cos(x+y)sinx-sin(x+y)cosx
问题描述:
化简cos(x+y)sinx-sin(x+y)cosx
答
原式=sin[x-(x+y)]=sin-y=-siny
答
cos(x+y)sinx-sin(x+y)cosx
=sin[x-(x+y)]
=sin(-y)
=-siny