Question

sin2a (1+tg2a tga)

Answer 1

$sin 2a(1+tan 2atan a)=sin 2aleft(1+cfrac{2tan^2a}{1-tan^2 a}right)=\=sin 2aleft(cfrac{1+tan^2a}{1-tan^2a}right)=cfrac{sin 2a}{cos 2a}=tan 2a$