RRB NTPC · Question 28
If A + B = 90°, then which of the following is correct? A. sin A = cos B B. sin A + cos B = 0 C. sin A – cos B = 1 D. sin A – cos B = 2
Show answer & explanation
Answer: (B) A
Explanation
If A + B = 90°, then B = 90° − A and cos B = cos(90° − A) = sin A.