Question

If sec 4A = cosec (A – 10°) and 4A is acute then A = ?

विकल्प

• 20°

• 25°

• 30°

• 40°

Answer 1

20°

Explanation:

sec 4A = cosec (A – 10°) 

⇒ cosec (90° – 4A) = cosec (A – 10°) 

⇒ 90° – 4A = A – 10° 

⇒ 5A = 100° 

⇒ A = 20°