# College Math Teaching

## January 23, 2015

### Making a math professor happy…

Filed under: calculus, class room experiment, elementary mathematics — Tags: , — collegemathteaching @ 10:28 pm

Calculus III: we are talking about polar curves. I give the usual lesson about how to graph $r = sin(2 \theta)$ and $r = sin(3 \theta)$ and give the usual “if $n$ is even, the graph of $r = sin (n \theta)$ has $2n$ petals and if $n$ is odd, it has $n$ petals.

Question: “does that mean it is impossible to have a graph with 6 petals then”? 🙂

Yes, one can have intersecting petals and one try: $r = |sin(3 \theta) |$. But you aren’t going to get it without a trick of some sort.