Answer
$\left(-\frac{1}{2},\frac{\sqrt3}{2}\right)$
Work Step by Step
By definition: $x=r\cdot \cos(\theta)$ and $y=r\cdot \sin(\theta)$.
Here $r=-1, \theta=\frac{-\pi}{3}$.
Hence, after plugging these in:
$x=-1\cdot \cos(\frac{-\pi}{3})=-1\cdot(0.5)=-0.5$
$y=-1\cdot \sin(\frac{-\pi}{3})=-1\cdot\frac{-\sqrt3}{2}=\frac{\sqrt3}{2}$
The point has coordinates $\left(-\frac{1}{2},\frac{\sqrt3}{2}\right)$ in the rectangular coordinate system.