Verified answer

Объяснение:

[tex]\displaystyle\\\frac{sin(\frac{\pi }{2}+\alpha )-cos(\pi +\alpha ) }{sin(2\pi -\alpha )} =\frac{cos\alpha -(-cos\alpha )}{-sin\alpha } =-\frac{2*cos\alpha }{sin\alpha } =-2ctg\alpha.[/tex]