## Calculus (3rd Edition)

Circle of radius 2 and centered at the origin. Circle of radius $\sqrt 2$ and centered at the origin. The point $(2,0)$.
(a) $r=2$ is a circle of radius 2 and centered at the origin. (b) $r^2=2$ is a circle of radius $\sqrt 2$ and centered at the origin. (c) $r\cos \theta =2 \Longrightarrow x=2$; the point $(2,0)$ which is the closest to the origin.