If sec 4A = cosec (A – 10°) and 4A is acute then ∠A = ?
We are given that: sec 4A = cosec (A – 10°)
∴We can rewrite it as: cosec (90° – 4A) = cosec (A – 10°)
On comparing both sides, we get,
90° – 4A = A – 10 °
⇒ A + 4A = 90° + 10°
⇒ 5A = 100°
⇒ A = 20°