Выполни задание

Упрости выражения:

1. \(\dfrac{\cos(\alpha+\dfrac{7\pi}{2})}{\sin(\alpha+4\pi)} = \) [ ];
2. \(\dfrac{\sin (\alpha +\dfrac{3\pi}{2})\cdot\cos(\alpha+5\pi)}{\cos(\alpha+\pi)\cdot \cos(\dfrac{\pi}{2}-\alpha)} = \) [ ].