Cosx/2(cosx+1)=0 СРОЧНО

Решите задачу:

$\frac{cosx}{2(cosx+1)} =0\quad \to \quad \left \{ {{cosx=0} \atop {cosx+1\ne 0}} \right. \; \left \{ {{cosx=0} \atop {cosx\ne -1}} \right. \\\\ \left \{ {{x=\frac{\pi}{2}+\pi n,\; n\in Z} \atop {x\ne \pi +2\pi k,\; k\in Z}} \right. \\\\Otvet:\; \; \; x=\frac{\pi}{2}+\pi n,\; n\in Z.$

$cos\frac{x}{2}(cosx+1)=0\\\\1)cos\frac{x}{2}=0,\frac{x}{2}=\frac{\pi}{2}+\pi n,x=\pi +2\pi n,n\in Z\\\\2)cosx=-1,x=\pi +2\pi k,k\in Z$