Cos2x minus sin2x minus sin 2x cos2 x sin2xcos2x sin 2x v

Cos^2x minus sin^2x minus sin 2x = (cos^2 x - sin^2x)/cos2x + sin 2x verify the identity

cos^2x -sin^2x -sin2x = (cos^2x -sin^2x)/(cos2x + sin2x

LHS we know cos2x = cos^2x -sin^2x

So, LHS : cos^2x -sin^2x -sin2x

= cos2x -sin2x

RHS : (cos^2x -sin^2x)/cos2x + sin2x

= cos2x/cos2x +sin2x

= 1+ sin2x

Now LHS and RHS cannot be same after simplication

RHS