Question

ооооочень срочно... нужно упростить

Answer 1

$\frac{\sin(-\alpha)+\cos(\pi+\alpha)}{1+2\cos\left(\frac\pi2-\alpha\right)\cos(-\alpha))}=\frac{-\sin\alpha-\cos\alpha}{1+2\sin\alpha\cos\alpha}=-\frac{\sin\alpha+\cos\alpha}{1+\sin\alpha\cos\alpha}=\\=-\frac{\sin\alpha+\cos\alpha}{\sin^2\alpha+\cos^2\alpha+2\sin\alpha\cos\alpha}=-\frac{\sin\alpha+\cos\alpha}{(\sin\alpha+\cos\alpha)^2}=-\frac1{\sin\alpha+\cos\alpha}$