Question

6. If A and (2A – 45°) are acute angles such that sin A = cos (2A – 45°), then tan A is equal to

(a) 0 (b) (c) 1 (d) √3​

Answer 1

Answer:

given

sinA = cos (2A - 45°)

since, sinA = cos (90° - A)

so cos (90° - A) = cos (2A- 45°)

so, 90- A = 2A- 45

3A = 90+ 45 = 135

A = 45°

therefore, tanA = tan45° = 1