Given the Polar Coordinates:

You need to use the following formulas:

Remember that Polar Coordinates have this form:

And Rectangular Coordinates have this form:

In this case, you can identify that:

Therefore, you can substitute values into the formulas:

Evaluating, you get:
![\begin{gathered} x=-\frac{9\sqrt[]{3}}{2} \\ \\ y=(9)/(2) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/p12qswlk0o6bejf4zmdkttfoluzf6f6vm4.png)
Hence, the answer is:
![(-\frac{9\sqrt[]{3}}{2},(9)/(2))](https://img.qammunity.org/2023/formulas/mathematics/high-school/l6ac5p58ju4whmymjm6qxymdco7opnj4ez.png)