If Cos 3θ = Sin (θ - 34o), then the value of θ as an acute angle is:
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Correct answer: C
Explanation
The correct answer is option 3 i.e 31o
⇒ Cos 3θ = Sin (θ - 34o)
⇒ Cos 3θ = Cos (90o - θ + 34o)
⇒ 3θ = 124o - θ ± 2nπ
For acute angle n would be zero
⇒ 4θ = 124o
⇒ θ = 31o