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Prove the following:\(\frac{sin^3\theta+cos^3\theta}{sin\theta+cos\theta} + \frac{sin^3\theta-cos^3\theta}{sin\theta-cos\theta}=2\)sin3θ+cos3θ/sinθ+cosθ +sin3θ-cos3θ/sinθ-cosθ =2 |
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Answer» =2(\(\frac{sin^2\theta}{cos^2\theta}+\frac{1}{cos^2\theta}\)) = 2(\(\frac{sin^2\theta+1}{cos^2\theta}\)) =2 (\(\frac{1+ sin^2\theta}{1-sin^2\theta}\)) =R.H.S = (sin2 θ + cos2 θ – sin θ cos θ) + (sin2 θ + cos2 θ + sinθ cosθ) = 2 (sin2 θ + cos2 θ) = 2(1) = 2 = R.H.S |
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