Question

If sin A = cos B and A ≠ B then the relation between angles A and B is ______.

Options

• A + B = 180°

• A − B = 90°

• B − A = 90°

• A + B = 90°

Answer 1

If sin A = cos B and A ≠ B then the relation between angles A and B is A + B = 90°.

Explanation:

By complementary angle properties, cos B = sin(90° − B). Therefore, sin A = sin(90° − B) implies A = 90° − B, which rearranges to A + B = 90°.