1-2cos^2a/1/2sin4a=tg2a-ctg2a

Question

1-2cos^2a/1/2sin4a=tg2a-ctg2a

Answer 1

(2-sin(4*a)*ctg(2*a))/sin(4*a)=tg(2*a)
1/(sin(2a)*cos(2a))-cos(2a)/sin(2a) =(1-cos^2(2a))/(sin(2a)*cos(2a))=
=sin^2(2a)/(sin(2a)*cos(2a))=tg(2*a)