(tan2x)/(2tanx)-sec^2x/(1-tan^2x)tan2x2tanx−sec2x1−tan2x
=(2tanx)/((2tanx)(1-tan^2x))-sec^2x/(1-tan^2x)=2tanx(2tanx)(1−tan2x)−sec2x1−tan2x
=1/(1-tan^2x)-sec^2x/(1-tan^2x)=11−tan2x−sec2x1−tan2x
=(1-sec^2x)/(1-tan^2x)=1−sec2x1−tan2x
=(1-1-tan^2x)/(1-tan^2x)=1−1−tan2x1−tan2x
=tan^2x/(tan^2x-1)=tan2xtan2x−1