Math, asked by abhishekranjan8, 1 year ago

prove that sinA -2sin³A=(2cos³A-co0sA)tan A

Answers

Answered by rakeshmohata

HOPE U LIKE MY PROCESS
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$\sin( \alpha ) - 2 \sin ^{ 3} ( \alpha ) \\ \\ = \sin( \alpha ) (1 - 2 \sin ^{2} ( \alpha ) ) \\ \\ = \sin( \alpha ) (1 - 2(1 - \cos ^{2} ( \alpha ) ) ) \\ \\ = \sin( \alpha ) ( 1 - 2 + 2\cos ^{2} ( \alpha ) ) \\ \\ = \sin( \alpha ) (2 \cos ^{2} ( \alpha ) - 1) \\ \\ = \frac{ \sin( \alpha ) }{ \cos( \alpha ) } (2 \cos ^{3} ( \alpha ) - \cos( \alpha ) ) \\ \\ = (2 \cos ^{3} ( \alpha ) - \cos( \alpha ) ) \tan( \alpha )$
Hence proved.

Hope this is ur required answer

Proud to help you

abhishekranjan8: HI

rakeshmohata: hi

abhishekranjan8: WHAT HAVE YOU DONE AFTER sinA(2cossquareA)

rakeshmohata: multiplied and divided cos a

rakeshmohata: I mean.. तो make sinA to tanA.. i hv to divide cosA.. and to balance it.. i multiplied cosA inside

abhishekranjan8: OK AND THANKS

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