Question

If A + B = 90°, then the value of tan² A – cot² B is ______.

Answer 1

If A + B = 90°, then the value of tan² A – cot² B is 0.

Explanation:

B = 90° – A, so cot B = cot (90° – A) = tan A. 

Therefore tan² A – cot² B = tan² A – tan² A = 0.