Question

CosA=SinB,find cos(A+B)

Answer 1

Step-by-step explanation:

cosA=sinB

cosA=cos(90-B)

A=90-B

A+B=90

so,cos90=1

Answer 2

Given , CosA = sinB-----(1)

=> CosA = Cos(90°-B)

=> A = 90° -B => A + B = 90°

=> Cos(A+B) = Cos(90°) = 0