Line in polar coordinates I just wanted to clarify something. A line in polar coordinates has the parameterization of $\theta = k\pi$ for $k \in \mathbb{R}$ right? Or am I missing something?

Hint: Let $x = r \cos \theta$ and $y= r \sin \theta$ and see if you can find the polar equations for
$$y = mx + b \\ y = x + b \\ y = x$$  For the third equation, what do you notice?
