EPICYCLOID - 2 reference results
In geometry, an epicycloid is a plane curve produced by tracing the path of a chosen point of a circle — called epicycle — which rolls without slipping around a fixed circle. It is a particular kind of roulette.
If the smaller circle has radius r, and the larger circle has radius R = kr, then the parametric equations for the curve can be given by:
If k is an integer, then the curve is closed, and has k cusps (i.e., sharp corners, where the curve is not differentiable).
If k is a rational number, say k=p/q expressed in simplest terms, then the curve has p cusps.
If k is an irrational number, then the curve never closes, and fills the space between the larger circle and a circle of radius R+2r.
The epicycloid is a special kind of epitrochoid.
An epicycle with one cusp is a cardioid.
An epicycloid and its evolute are similar.
See also
- Special cases: Cardioid, Nephroid
- Cycloid
- Hypocycloid
- Epitrochoid
- Hypotrochoid
- Spirograph
- Deferent and epicycle
References
- J. Dennis Lawrence (1972). A catalog of special plane curves. Dover Publications.
External links
- Epicycloid, MathWorld
- "Epicycloid" by Michael Ford, The Wolfram Demonstrations Project, 2007
Wikipedia, the free encyclopedia © 2001-2006 Wikipedia contributors (Disclaimer)
This article is licensed under the GNU Free Documentation License.
Last updated on Friday September 26, 2008 at 14:45:18 PDT (GMT -0700)
View this article at Wikipedia.org - Edit this article at Wikipedia.org - Donate to the Wikimedia Foundation
This article is licensed under the GNU Free Documentation License.
Last updated on Friday September 26, 2008 at 14:45:18 PDT (GMT -0700)
View this article at Wikipedia.org - Edit this article at Wikipedia.org - Donate to the Wikimedia Foundation
Copyright © 2009, Dictionary.com, LLC. All rights reserved.