Poinsot's spirals
In mathematics, Poinsot's spirals are two spirals represented by the polar equations where csch is the hyperbolic cosecant, and sech is the hyperbolic secant.
[1] They are named after the French mathematician Louis Poinsot.
This geometry-related article is a stub.
You can help Wikipedia by expanding it.
The Poinsot spiral r=csch(θ/3).
The Poinsot spiral r=sech(θ/3).