Question

If sec3x = cosec(3x - 45°), where 3x is an acute angle, then x is equal to:

• A. 35°
• B. 45°
• C. 22.5°
• D. 27.5°

Answer 1

Answer:

C. 22.5°

Solution: Given: sec3x = cosec(3x - 45°) Concept used: cosec(90 - θ) = secθ Calculation: sec3x = cosec(3x - 45°) ⇒ cosec(90° - 3x) = cosec(3x - 45°) ⇒ 90 - 3x = 3x - 45° ⇒ 6x = 135° ⇒ x = 22.5° ∴ The value of x is 22.5°.