If sec 2x = cosec (2x - 30°) where 2x is an acute angle find the value of 3x.

90° 60° 45° 30°

90°

We know that if sec A = cosec B, then A + B = 90° ATQ, sec 2x = cosec (2x - 30°) ⇒ 2x + 2x - 30° = 90° ⇒ 4x = 120° ⇒ x = 30° ⇒ 3x = 90°