InterviewSolution
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If \(sin\left( {A - B} \right) = \frac{1}{2}\) and \(\cos \left( {A + B} \right) = \frac{1}{2}\) where A > B > 0 and A + B is an acute angle, then the value of angle B is1). π/62). π/123). π/44). π/2 |
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Answer» $(sin\left( {A - B} \right) = \frac{1}{2})$ $(\because\sin \frac{\pi }{6} = \frac{1}{2})$ ∴ A – B = π/6…..(1) And, $(cos\left( {A + B} \right) = \frac{1}{2})$ $(\because\cos \frac{\pi }{3} = \frac{1}{2})$ ∴ A + B = π/3…..(2) (2) – (1) A + B – A + B = π/3 – π/6 ⇒ 2B = π/6 ⇒ B = π/12 |
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