[Potironette]

Thanks for the responses!

I wasn't sure if the orange force would exist or not because I was wondering if there needed to be a force towards the side in order for a ball on a string to swing around in a circle. Apparently that's a fictitious force though..?

I don't have the sheet with me anymore, but I think the problem was: change the polar equation into a coordinate equation.
The polar equation I was given was: theta = -pi/2
(Actually, now that I think about is, is theta = -pi/2 the same as the coordinate equation x = 0 because theta = -pi/2 means that (-n, -pi/2) and (n, -pi/2) are both included?)