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Prove that: (i) sin 3x+"sin" 2x-"sin"...

Prove that:
(i) `sin 3x+"sin" 2x-"sin" x`
=`4 sin x cos((x)/(2))cos((3x)/(2))`
(ii) `("sin" 3x+"sin" x)"sin" x+(cos 3x-cos x)cos x=0.`

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MODERN PUBLICATION-TRIGONOMETRY-Exercise 3(g)Long Answer type Question-I
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