Answer
$(-4.98,-3.85)$
Work Step by Step
By definition: $x=r\cdot \cos(\theta)$ and $y=r\cdot \sin(\theta)$.
Here, we have $r=6.3 \text{ and } \theta=3.8$.
Hence, after plugging these in:
$x=6.3\cdot \cos(3.8)\approx-4.98$
$y=6.3\cdot \sin(3.8)\approx-3.85$
The point has coordinates $(-4.98,-3.85)$ in the rectangular coordinate system.