化简[sin(2A+B)]/sinA-2cos(A+B)

来源:学生作业学帮网 编辑:学帮网 时间:2024/05/16 10:28:32

化简[sin(2A+B)]/sinA-2cos(A+B)

[sin(2A+B)]/sinA-2cos(A+B)
=[sin(A+B+A)]/sinA-2cos(A+B)
=[sin(A+B)cosA+cos(A+B)sinA]/sinA-2cos(A+B)
=[sin(A+B)cosA-cos(A+B)sinA]/sinA
=sin(A+B-A)/sinA
=sinB/sinA