Prove that x 3x + 3x 9x + 9x 27x = 1 2 ( 27x - x)

MATHEMATICS · Subjective · A Level · Mathematics · Trigonometry · Trigonometry

Problem

Prove that sin⁡xcos⁡3x+sin⁡3xcos⁡9x+sin⁡9xcos⁡27x=12(tan⁡27x−tan⁡x)\frac{\sin x}{\cos 3x} + \frac{\sin 3x}{\cos 9x} + \frac{\sin 9x}{\cos 27x} = \frac{1}{2} (\tan 27x - \tan x)

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