\[1)\ 2\cos x + \sin x = 0\ \ \ \ \ |\ :\cos x\]
\[2 + tg\ x = 0\]
\[tg\ x = - 2\]
\[x = - arctg\ 2 + \pi n.\]
\[Ответ:\ - arctg\ 2 + \pi n.\]
\[2)\sin x + \sqrt{3}\cos x = 0\text{\ \ \ }\ |\ :\cos x\]
\[tg\ x + \sqrt{3} = 0\]
\[tg\ x = - \sqrt{3}\]
\[x = - arctg\ \sqrt{3} + \pi n = - \frac{\pi}{3} + \pi n.\]
\[Ответ:\ - \frac{\pi}{3} + \pi n.\]