Question

If 2 cos 3θ = 1 then θ = ?

पर्याय

• 10°

• 15°

• 20°

• 30°

Answer 1

20°

Explanation:

`cos 3θ = 1/2 = cos 60^circ`

⇒ 3θ = 60°

⇒ θ = 20°