If you have a parametric equation grapher, graph the equations over the given intervals.
$$x=3 \cos t+\cos 3 t, \quad y=3 \sin t-\sin 3 t ; \quad 0 \leq t \leq 2 \pi$$
What happens if you replace 3 with -3 in the equations for $x$ and
$y ?$ Graph the new equations and find out.