prove if possible that:- (1-tan2A)/ (1+tan2A) = cos2A - sin2A - Maths - Introduction to Trigonometry

Question

prove if possible that:-
(1-tan2A)/ (1+tan2A) = cos2A -
sin2A

Varun.Rawat · Accepted Answer

RHS = cos2θ - sin2θ= cos2θ - sin2θ cos2θ + sin2θ    as,  cos2θ + sin2θ = 1=cos2θcos2θ - sin2θcos2θcos2θcos2θ + sin2θcos2θ     =1 - tan2θ1 + tan2θ     as, sin θcos θ = tan θ=LHS