Just want to confirm whether one includes the origin when drawing rays (polar form) in the form of $$\theta=k\quad\text{where k is a real constant}$$
I was pretty sure it wasn't meant to be included because $$\theta=\tan^{-1}\left(\frac{y}{x}\right)$$ which is undefined for (0,0) but after seeing my professor and some other people include it, I'm very confused.
What do you guys think?
Thanks