Answer
$r = 2-cos~\theta$
This graph is a limacon.
We can see this graph below:
Work Step by Step
$r = 2-cos~\theta$
When $\theta = 0^{\circ}$, then $r = 2-cos~0 = 1$
When $\theta = 30^{\circ}$, then $r = 2-cos~30^{\circ} = 1.13$
When $\theta = 60^{\circ}$, then $r = 2-cos~60^{\circ} = 1.5$
When $\theta = 90^{\circ}$, then $r = 2-cos~90^{\circ} = 2$
When $\theta = 120^{\circ}$, then $r = 2-cos~120^{\circ} = 2.5$
When $\theta = 180^{\circ}$, then $r = 2-cos~180^{\circ} = 3$
When $\theta = 240^{\circ}$, then $r = 2-cos~240^{\circ} = 2.5$
When $\theta = 270^{\circ}$, then $r = 2-cos~270^{\circ} = 2$
When $\theta = 300^{\circ}$, then $r = 2-cos~300^{\circ} = 1.5$
When $\theta = 330^{\circ}$, then $r = 2-cos~330^{\circ} = 1.13$
This graph is a limacon.
We can see this graph below:
