Answer
$(2,2\sqrt 3)$
Work Step by Step
Step 1. See plot; move to $\theta=\frac{4\pi}{3}$ and use $r=-4$ to get the point.
Step 2. Using the formulas $x=r\ cos\theta$ and $y=r\ sin\theta$, we have $x=-4cos\frac{4\pi}{3}=2$ and $y=-4sin\frac{4\pi}{3}=2\sqrt 3 $, giving a point $(2,2\sqrt 3)$
