\tan ( x - y ) = \frac { \tan x - \tan y } { 1 + \tan x \tan y }

1.	\tan ( x - y ) = \frac { \tan x - \tan y } { 1 + \tan x \tan y }
Answer» tan(x-y) = sin(x-y)/cos(x-y) = (sin x.cos y - cos x.sin y)/(cos x.cosy + sin x.sin y) Divide the numerator and the denominator by cos x.cos y tan(x-y) = (sin x/cosx- sin y/cos y) / (1 + sin x.sin y/cos x.cos y) = (tanx- tan y)/(1+ tan x.tan y) Why are u posting formulas what is ur question, are u asking for the proof of the formula

Answer»

tan(x-y) = sin(x-y)/cos(x-y)

= (sin x.cos y - cos x.sin y)/(cos x.cosy + sin x.sin y)

Divide the numerator and the denominator by cos x.cos y

tan(x-y) = (sin x/cosx- sin y/cos y) / (1 + sin x.sin y/cos x.cos y)

= (tanx- tan y)/(1+ tan x.tan y)

Why are u posting formulas what is ur question, are u asking for the proof of the formula

Discussion