证明sinAcosB+cosAsinB=sin(A+B)

2025-03-11 01:37:52
推荐回答(1个)
回答1:

sin(A+B)
=cos[π/2-(A+B)]
=cos[(π/2-A)-B]
=cos(π/2-A)cosB+sin(π/2-A)sinB
=sinAcosB+cosAsinB