Question

4sinθ sin(120+θ) sin(60+θ) = sin 3θ​

Answer 1

$Sin(60−θ).Sinθ.Sin(60+θ)  = φ</p><p></p><p></p><p>(Sin60cosθ−Sinθcos60)  sinθ  (sin60cosθ+sinθcos60)</p><p></p><p></p><p>⇒ (Sin260cos2θ−Sin2θcos260) Sinθ  = φ</p><p></p><p></p><p>⇒(43cos2θ−4sin2θ)sinθ ⇒ sinθ (43−sin2θ)</p><p></p><p></p><p>⇒(3Sinθ−4Sin3θ)41=4Sin3θ </p><p></p><p>$