Question

tan(A+B)-tanA/1 +tan(A+B).tanB=tanB

Answer 1

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We know that,

tan(x-y)

=[tanx-tany]/(1+tanx-tany)

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Here,

A+B = x , A = y

Now,

LHS =tan(A+B)-tanA/1 +tan(A+B).tanB

= (tanx-tany)/(1+tanxtany)

= tan(x-y)

= tan [A+B-A]

= tan B

= RHS

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