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Prove the identity: sin 2x/(1 – cos 2x) = cot x |
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Answer» Let us consider the LHS sin 2x/(1 – cos 2x) As we know that cos 2x = 1 – 2 sin2 x Sin 2x = 2 sin x cos x Therefore, sin 2x/(1 – cos 2x) = (2 sin x cos x)/(1 – (1 – 2sin2 x)) = (2 sin x cos x)/(1 – 1 + 2sin2 x)] = [2 sin x cos x/2 sin2 x] = cos x/sin x = cot x = RHS Thus proved. |
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