# Parametric T-shirts

I’m excited to share my new TeeMill site, selling T-shirts based on graphs of parametric equations.

There are three designs currently available, and all can be bought in loose fit or fitted, and with or without the equations that created the design displayed underneath.

You can also find GeoGebra files, where you can play with the graphs of the equations yourself, here.

# Spin, Laugh and Dance

I’d like to introduce you to the graph of $x=\sin(f_1t)e^{d_1t}$, $y=\sin(f_2t)e^{d_2t}$, a curve that spins, laughs and dances.

Continue reading Spin, Laugh and Dance

# Rupert Polyhedra: Cube

Last week, I wrote about Rupert polyhedra, and how a tetrahedron has the Rupert property. The idea dates back to the 1600s, when Prince Rupert of the Rhine won a bet that it was possible to make a hole in a cube that was large enough for an identical cube to pass through, so let’s look at how the Rupert property works for a cube.