证明sin(A+B)=sinAcosB+cosAsinB

2024-11-26 08:53:20
推荐回答(1个)
回答1:

sin(A+B)
=cos[90-(A+B)]
=cos[(90-A)-B]
=cos(90-A)cosB+sin(90-A)sinB
=sinAcosB+cosAsinB