Question

Спростіть вираз**************

Answer 1

$2)~3 + 3ctg^{2} (\alpha) - \frac{1}{sin^{2}(\alpha) } = 3 + 3ctg^{2}(\alpha) - (1 + ctg^{2} (\alpha)) = 3 + 3ctg^{2}(\alpha) - 1 - ctg^{2} (\alpha) = \boxed{ 2 + 2ctg^{2}(\alpha)}.$