## Precalculus (6th Edition) Blitzer

The graphs of $r=a\sin n\theta$ and $r=a\cos n\theta$, $a\ne 0$, are called rose curves. If $n$ is even, the rose has $2n$ petals. If $n$ is odd, the rose has $n$ petals.
The graphs of $r=asinn\theta$ and $r=a\cos n\theta$, $a\ne 0$, are like rose curves and the number of petals depends on the value of $n$. The number of petals will be two times $n$, if n is even and the number of petals will be the same as $n$ if n is odd. For example, if $r=asin4\theta$, then the number of petals will be 8, and if $r=a\cos 3\theta$, then the number of petals will be 3.