Question

2tan2(A)+tan(A)=0 , para valores positivos de 0° a 360°.

Answer 1

*$tg2 \alpha =\frac{2tg \alpha }{1-tg ^{2} \alpha }$

$2tg 2\alpha +tg \alpha =0$
$2tg2 \alpha =-tg \alpha$
$2( \frac{2tg \alpha }{1-tg ^{2} \alpha } )=-tg \alpha$
simplificando tg$\alpha$
$\frac{4}{1-tg ^{2} \alpha } =-1$
$4=tg ^{2} \alpha -1$
$tg \alpha = \sqrt{5}$