Given a point in coordinates form [tex](r,\theta)[/tex], one can compute the cartesian form like this:
[tex](r\cos\theta,r\sin\theta )[/tex]
We have:
[tex]r=6,\theta=-\dfrac{\pi}{5}[/tex]
We get the cartesian form then:
[tex]\left(6\cos-\dfrac{\pi}{5},6\sin-\dfrac{\pi}{5}\right)[/tex]
