# Difference between revisions of "Locus"

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− | '''Locus''' is essentially a synonym for [[set]]. It is used most frequently in [[geometry]]. | + | '''Locus''' is essentially a synonym for [[set]]. It is used most frequently in [[geometry]], to denote a set of points satisfying a certain geometric condition. |

+ | == Examples == | ||

+ | |||

+ | * A [[circle]] can be defined as the locus of all points that are a certain distance from a given center. | ||

+ | * If we have a line <math>l</math> and a point <math>P</math>, a [[parabola]] is the locus of all points <math>S</math> such that <math>SP=</math> the distance from <math>S</math> to <math>l</math>. | ||

+ | * If we have two points A and B, an [[ellipse]] is the locus of all points <math>S</math> such that <math>SA+SB</math> is equal to a given constant. | ||

+ | * Given two points <math>A</math> and <math>B</math> and a constant <math>k</math>, the locus of all points <math>P</math> that satisfy <math>\frac{PA}{PB} = k</math> is a circle (sometimes called an [[Apollonius circle]]). | ||

+ | |||

+ | [[Category:Geometry]] |

## Latest revision as of 01:58, 22 March 2011

*This article is a stub. Help us out by expanding it.*

**Locus** is essentially a synonym for set. It is used most frequently in geometry, to denote a set of points satisfying a certain geometric condition.

## Examples

- A circle can be defined as the locus of all points that are a certain distance from a given center.
- If we have a line and a point , a parabola is the locus of all points such that the distance from to .
- If we have two points A and B, an ellipse is the locus of all points such that is equal to a given constant.
- Given two points and and a constant , the locus of all points that satisfy is a circle (sometimes called an Apollonius circle).