Question

Нужно решить срочно?

Answer 1

$\frac{tg( \alpha - \pi)cos( \frac{ \pi }{2}+ \alpha)cos( \pi + \alpha)}{sin(- \alpha )ctg( \frac{3}{2} \pi + \alpha )} =$$\frac{tg( \alpha)(-sin(\alpha))(-cos(\alpha))}{sin(- \alpha )(-tg(\alpha))} =$$\frac{-(-sin(\alpha))(-cos(\alpha))}{sin(- \alpha )} = \frac{sin(\alpha)(-cos(\alpha))}{-sin(\alpha )} =$$-(-cos( \alpha )) = cos( \alpha )$