Pronunciation: /ˈfoʊ.kəs/ Explain
|Figure 1: Focus||
In geometry, a focus is a
related to the construction and properties of
have one focus. The focus of a circle is also center of the circle. Sometimes, it is
convenient to talk of a circle having two
focuses, meaning two focuses that occupy the same point. Similarly, a parabola is
sometimes considered to have a second focus at
both have two focuses.
- McAdams, David E.. All Math Words Dictionary, focus. 2nd Classroom edition 20150108-4799968. pg 81. Life is a Story Problem LLC. January 8, 2015. Buy the book
- Hustler, James Devereux. The Elements of the Conic Sections with the Sections of the Conoids. 3rd edition. pp 1-18. www.archive.org. J. Deighton and Sons. 1826. Last Accessed 7/11/2018. http://www.archive.org/stream/elementsofconics00hastuoft#page/1/mode/1up/search/focus. Buy the book
- Loomis, Elias. Elements of geometry and conic sections. www.archive.org. Harper & Brother, Publishers. 1849. Last Accessed 7/11/2018. http://www.archive.org/stream/elementsgeometr05loomgoog#page/n183/mode/1up/search/focus. Buy the book
- McAdams, David E.. Circle. allmathwords.org. All Math Words Encyclopedia. Life is a Story Problem LLC. 3/12/2009. http://www.allmathwords.org/en/c/circle.html.
Cite this article as:
McAdams, David E. Focus. 12/21/2018. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/f/focus.html.
12/21/2018: Reviewed and corrected IPA pronunication. (McAdams, David E.)
7/9/2018: Removed broken links, updated license, implemented new markup, implemented new Geogebra protocol. (McAdams, David E.)
1/7/2010: Added "References". (McAdams, David E.)
10/11/2008: Initial version. (McAdams, David E.)