sin(x+105°)cos(x-15°)-cos(x+105°)sin求化简
6个回答
根据公式sin(a-b)=sinacosb-cosasinb
所以原式=sin(x+105-x+15)=sin120°=√3/2
相关问题
sin(x+105°)cos(x-15°)-cos(x+105°)sin(x-15°)
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