Question

prove that (sin 7theta-sin theta) /(sin 8theta - sin 2theta) =cos 4 theta * sec 5 theta​

Answer 1

Answer:

Answer

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Correct option is

A

10

Given : sin7θ=cos2θ

⟹sin7θ=sin(90o−2θ)

⟹7θ=90o−2θ

⟹9θ=90o

⟹θ=10o

Hence, the answer is 10