Question

If sin 3θ = cos(θ – 6°) here  3θ and (θ – 6°) are acute angles, then find the value of θ.

Answer 1

Given :

sin 3θ = cos(θ – 6°)

or cos(90° – 3θ) = cos(θ – 6°) [∵ cos(90° – θ) = sin θ]

or 90° – 3θ = θ – 6°

or 3θ + θ = 90° + 6°

or 4θ = 96°

or θ = 96/4 = 24°