Envelope

Pronunciation: /ˈɛn vəˌloʊp/ ?

Animated image showing the creation of an envelope from a family of lines.
Figure 1: Creation of an envelope.

In mathematics, an envelope is a curve that is tangent to a family of lines or other geometric shapes.[1] Figure 1 shows the creation of an envelope from a family of lines. Manipulative shows two blue lines that are envelopes for a family of circles. Click on the blue points in manipulative 1 and drag them to change the figure.

Sorry, the GeoGebra Applet could not be started. Please make sure that Java 1.4.2 (or later) is installed and active in your browser (Click here to install Java now)
Manipulative 1: Envelopes of a family of circles. Created with GeoGebra.

Cite this article as:


Envelope. 2010-01-24. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/e/envelope.html.

Translations

Image Credits

Revision History


2010-01-24: Added "References" (McAdams, David.)
2008-11-18: Changed manipulative to GeoGebra (McAdams, David.)
2008-05-10: Initial version (McAdams, David.)

All Math Words Encyclopedia is a service of Life is a Story Problem LLC.
Copyright © 2005-2011 Life is a Story Problem LLC. All rights reserved.
Creative Commons License This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License