# Thread: Polar form

1. ## Polar form

How do you change the point ( 3, 9π/4) which is in polar form into rectangular form?

2. Originally Posted by jumpman23
How do you change the point ( 3, 9π/4) which is in polar form into rectangular form?
Have you been taught that $x = r \cos \theta$ and $y = r \sin \theta$ ....?