Упрости выражения

1. \(\cos \left(\pi- \alpha \right)+\tg \left(\pi+ \alpha \right)-\sin \left(\dfrac{3\pi}{2}+ \alpha \right)+\ctg \left(\dfrac{\pi}{2}+ \alpha \right)\) ;

2. \(\dfrac{\sin \left(\beta -\pi \right) \cos \left(2\pi -\beta \right) \sin \left(2\pi +\beta \right)}{\sin \left( \dfrac{\pi}{2}-\beta \right) \ctg \left(\pi -\beta \right) \ctg \left(\dfrac{3\pi}{2}+\beta \right)}\) .

Ответ: 1) [ ]; 2) [ ].