Sin8x=8sinxcosxcos2xcos4x proving trig identity?

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Ernestine · Answer 1 · 2017-11-30T08:46:26+0000

sin 8 x = 2 sin 4x cos 4x =
= 2 * 2 sin 2x cos 2x cos 4 x =
= 4 * 2 sin x cos x cos 2x cos 4x =
= 8 sin x cos x cos 2x cos 4x ( correct )