Question

Помогите решить:
$\frac{1-sin^{2}\alpha}{1-cos^{2}\alpha}$

Answer 1

$\frac{1 - {sin}^{2} \alpha }{1 - {cos}^{2} \alpha } = \frac{ {cos}^{2} \alpha }{ {sin}^{2} \alpha } = {ctg}^{2} \alpha = \frac{1}{{tg}^{2}\alpha}$