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COS (A + B).5. (i) If sin A =VIOsin B =115107prove that A + B = "; A and B being positive acute4angles. |
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Answer» Answer: answer is pie by four please mark my answer as brainliest. Step-by-step explanation: sin A = 1/√10 and sin B = 1/√5 We KNOW that sin2x + cos2x = 1 Thus, cos A = √(1 – sin2A) = 3/√10 cos B = √(1 – SIN2B) = 2/√5 As we know, sin(A + B) = sin A cos B + cos A sin B = (1/√10) (2/√5) + (3/√10) (1/√5) = (2 + 3)/ √50 = 5/(5√2) = 1/√2 sin(A + B) = sin π/4 {SINCE A and B are acute angles as per the GIVEN} Therefore, A + B = π/4 |
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