已知函数$f\left(x\right)=\sqrt{3}\sin x-\cos x,x\in R$，若$f\left(x\right)\ge 1$，则$x$的取值范围为

$\left\{\overline{)x}k\pi +\frac{\pi }{3}\le x\le k\pi +\pi ,k\in Z\right\}$ $\left\{\overline{)x}2k\pi +\frac{\pi }{3}\le x\le 2k\pi +\pi ,k\in Z\right\}$ $\left\{\overline{)x}k\pi +\frac{\pi }{6}\le x\le k\pi +\frac{5\pi }{6},k\in Z\right\}$ $\left\{\overline{)x}2k\pi +\frac{\pi }{6}\le x\le 2k\pi +\frac{5\pi }{6},k\in Z\right\}$