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प्रश्न
Prove that cos(30° + x) = `(sqrt(3) cos x - sin x)/2`
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उत्तर
cos(30° + x) = `(sqrt(3) cos x - sin x)/2`
cos(30° + x) = cos 30°. cos x – sin 30° sin x
= `sqrt(3)/2 cos x - 1/2 sin x`
cos(30° + x) = `(sqrt(3)cosx- sinx)/2`
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