I'm a little confused, I'm trying to express (3, 0°) into rectangular form. How do I do it with theta being 0°?

Please and thanks!

use the unit circle.

or

assuming its polar coordinates, you can change the basis by using the transformation:

x = r*cos(theta)
y = r*sin(theta)

where (r, theta) is the coordinate in polar form.

This post was edited by khemist on Sep 15 2013 12:23pm

Thank you! That helped so much!

If it's 0 degrees it's super easy, it's just going to be (3,0) since there will by no y-component. 0 degrees is along the positive x-axis. 180 degrees would be (-3,0) since it's along the negative x-axis. And similarly, 90 degrees and 270 degrees would be (0,3) and (0,-3) respectively.