sin(x+105°)cos(x-15°)-cos(x+105°)sin求化简 sin(x+105°)cos(x-15°)-cos_数学解答

sin(x+105°)cos(x-15°)-cos(x+105°)sin求化简
sin(x+105°)cos(x-15°)-cos(x+105°)sin(x-15°)

人气：140 ℃　时间：2020-04-07 20:33:11

解答

根据公式sin（a-b）=sinacosb-cosasinb
所以原式=sin(x+105-x+15）=sin120°=√3/2