Math Help - Trigonometric Identities

1. Trigonometric Identities

What is equivalent to the value of sin(A+B) if sinA = cosB?

I know the answer is 1. I just can't see how to get their using the trig identities.

2. Originally Posted by MATNTRNG
What is equivalent to the value of sin(A+B) if sinA = cosB?

I know the answer is 1. I just can't see how to get their using the trig identities.
If sinA=cosB, then cosA=sinB also. Why?

$cos^2B+sin^2B$

or

$sin^2A+cos^2A$