Given,tan5𝜋12- tan𝜋121 + tan5𝜋12 tan𝜋12tan (x - y)=tan x - tan y1 + tan x tan y= tan 5𝜋12-𝜋12= tan 4𝜋12= tan 𝜋3tan5𝜋12- tan𝜋121 + tan5𝜋12 tan𝜋12=3
Problem 2 :
tan13𝜋12+ tan7𝜋121 - tan13𝜋12 tan7𝜋12
Solution :
Given,tan13𝜋12+ tan7𝜋121 - tan13𝜋12 tan7𝜋12tan (x + y)=tan x + tan y1 - tan x tan y= tan 13𝜋12+7𝜋12= tan 20𝜋12= tan 5𝜋3= tan 2𝜋3+ 𝜋= tan 2𝜋3=-3tan13𝜋12+ tan7𝜋121 - tan13𝜋12 tan7𝜋12=-3
Problem 3 :
tan(a - b)+ tan(b)1 - tan(a - b) tan(b)
Solution :
Given,tan(a - b)+ tan(b)1 - tan(a - b) tan(b)tan (x + y)=tan x + tan y1 - tan x tan y= tan ((a - b)+ b)= tan atan(a - b)+ tan(b)1 - tan(a - b) tan(b)= tan a