To convert a polar point (r, θ) to rectangular coordinates (x, y) use the formula:
[tex]\begin{gathered} x=r\cos\theta \\ y=r\sin\theta \end{gathered}[/tex]
Therefore,
[tex]x=5\cos(\frac{11\pi}{4})=-\frac{5\sqrt{2}}{2}[/tex]
[tex]y=5\sin(\frac{11\pi}{4})=\frac{5\sqrt{2}}{2}[/tex]
Therefore, the required rectangular coordinates is:
[tex](-\frac{5\sqrt{2}}{2},\frac{5\sqrt{2}}{2})[/tex]
(-5√2/2, 5√2/2)
