sin(x+105°)cos(x-15°)-cos(x+105°)sin求化简
问题描述:
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°)
答
根据公式sin(a-b)=sinacosb-cosasinb
所以原式=sin(x+105-x+15)=sin120°=√3/2