Question

化简：cos(π2+α)+sin(π?α)?sin(π+α)?sin(?α)=______

化简：cos(π2+α)+sin(π?α)?sin(π+α)?sin(?α)=______．

Answer 1

cos(

π

2

+α)+sin(π?α)?sin(π+α)?sin(?α)
=-sinα+sinα+sinα+sinα=2sinα
故答案为：2sinα