Answer
See graph, symmetric with respect to the polar axis.
Work Step by Step
1. See graph, for $r=4cos\theta$, it is a circle with center $(0,2)$, radius$=2$ (rectangular system).
2. To test for symmetry with respect to the polar axis, replace $\theta$ with $-\theta$, we have $r=4cos(-\theta)=4cos\theta$, thus it is symmetric with respect to the polar axis.
