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If 7cos^2 A +3sin^2 A = 4 find value of TanA |
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Answer» 3sin2A + 7cos2A = 4 =3sin2A + 3cos2A + 4cos2A = 4 =4cos2A + 3(sin2A + cos2A) = 4 --------(sin2A + cos2A =1) =4cos2A + 3 = 4 =4cos2A = 4 – 3 = 1 =cos2A = 1/4 =cosA = √1/4 =cosA = 1/2 =cosA =cos60 (cos60 = 1/2) =A = 60 Therefore tanA = √3 (tan60 = √3) |
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