Question

tg^2a(2cos^2a+sin^2a-1)
помогите пожалуйста

Answer 1

$tg^{2} \alpha (2 cos^{2} \alpha + sin^{2} \alpha -1)$
$tg^{2} \alpha (2 cos^{2} \alpha - cos^{2} \alpha)$
$tg^{2} \alpha * cos^{2} \alpha$
$tg^{2} \alpha = \frac{ sin^{2} \alpha }{cos^{2} \alpha }$
$\frac{ sin^{2} \alpha }{cos^{2} \alpha } * cos^{2} \alpha$
$sin^{2} \alpha$