How do you solve $tan(x+ y) = (tan x + tan y) / (1 - tan x tan y)$ ?

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Answer 1 · 2015-04-16T17:11:36

It is a trignometrical identity, there is nothing there to solve. The identity is arrived at by simplifying the identities in $sin(x+y)/cos(x+y)$

= $(sinx cosy +cosx siny)/(cosx cosy -sinxsiny)$ .

Divide the numerator as well as the denominator by cos x cosy to get

$(tanx +tany)/(1-tanx tany)$

How do you solve tan(x+ y) = (tan x + tan y) / (1 - tan x tan y)tan(x+ y) = (tan x + tan y) / (1 - tan x tan y)?