The Tangent Indicatrix of a Curve of Constant Precession is a spherical helix. The equation of a spherical helix on a Sphere with Radius making an Angle with the -axis is

(1) | |||

(2) | |||

(3) |

The projection on the -plane is an Epicycloid with Radii

(4) | |||

(5) |

**References**

Scofield, P. D. ``Curves of Constant Precession.'' *Amer. Math. Monthly* **102**, 531-537, 1995.

© 1996-9

1999-05-26