SOLUTION: Using tanx=sinx/cosx, prove the addition formula for tangent, tan(A+B)=(tanA+tanB)/(1-tanAxtanB).

Question 196593: Using tanx=sinx/cosx, prove the addition formula for tangent, tan(A+B)=(tanA+tanB)/(1-tanAxtanB).

Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
Since , we can say

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Start with the given equation.

Expand sine using the sum difference identity

Expand cosine using the sum difference identity

Divide EVERY term by

Reduce and simplify

Divide EVERY term by

Reduce and simplify

So this verifies

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