Answer
$$(2,\:-\frac{\pi }{6})$$
Work Step by Step
Converting the Cartesian coordinates to polar coordinates, we find:
$$r=\sqrt{\left(-\sqrt{3}\right)^2+1^2} =2 \\ θ=\arctan \left(\frac{1}{-\sqrt{3}}\right) = -\frac{\pi }{6}$$
Thus, it follows:
$$(2,\:-\frac{\pi }{6})$$