# math

If TanA=k.TanB prove that (k+1)sin(A-B)=(k-1)sin(A+B).

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2. k tan B = tan A

k sin B / cos B = sin A / cos A

k sin B cos A = sin A cos b

k (2 sin B cos A) = 2 sin A cos B

k (sin(A+B) - sin (A-B)) = sin (A-B) + sin(A+B)

k sin (A+B) - sin (A+B) = sin (A-B) + k sin (A-B)

(k-1) sin (A+B) = (k+1) sin (A-B)

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5. Thanks

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6. It is very useful for me thanku very much

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