Question

$frac{(sin(- alpha ) + cos(- alpha ))^2 -1}{-sin(- alpha )}$

Answer 1

$frac{(sin(-a)+cos(-a))^2-1}{-sin(-a)}=frac{(-sina+cosa)^2-1}{sina} = frac{sin^2a-2sinacdot cosa+cos^2a-1}{sina} =\\= frac{1-2sinacdot cosa-1}{sina} = frac{-2sinacdot cosa}{sina} =-2cdot cosa$