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प्रश्न
Express the following as a sum or difference
sin 4x cos 2x
उत्तर
sin A cos B = `1/2`[sin (A + B) + sin (A – B )]
Take A = 4x , B = 2x
sin 4x . cos 2x = `1/2`[sin(4x + 2x) + sin(4x – 2x)]
sin 4x . cos 2x = `1/2`[sin 6x + sin 2x]
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