Problem 19 - Entrance Test

The value of (1 + tan² A)/(1 + cot² A) is

A. tan² AB. cot² AC. sin² AD. cos² A

Correct: A

1+tan² A=sec² A, 1+cot² A=csc² A. Ratio sec² A/csc² A = sin² A/cos² A = tan² A.