Question

cos 9A = sin A

cos 9A = cos (90-A)

9A = 90 - A

10A = 90

A = 9

So tan 5A = tan 45 = 1

Answer 1

Step-by-step explanation:

cos 9A = sin A

cos 9A = cos (90-A)

9A = 90 - A

10A = 90

A = 9

So tan 5A = tan 45 = 1