rectangular coordinates and polar coordinates are related to each other by the following relation

On polar coordinates, the first coordinate is the radius and the second the angle. Using this information, we have

Solving thiose expressions, we have
![\begin{cases}x=6\cos (11\pi)/(6)=6\cdot(\frac{\sqrt[]{3}}{2})=3\sqrt[]{3} \\ y=6\sin (11\pi)/(6)=6\cdot(-(1)/(2))=-3\end{cases}](https://img.qammunity.org/2023/formulas/mathematics/high-school/7zzak57swcnv2iotbcv7shd16v44lc9pi8.png)
Then, the coordinates of the point Q are
![(3\sqrt[]{3},-3)](https://img.qammunity.org/2023/formulas/mathematics/high-school/fsz0exmgois0wkrg1dzqxemem33e45ys1x.png)