Difference between revisions of "Open set"
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(How is a ball different from a solid sphere, and how is this relevant?) |
(arcane and esoteric - give us basic math, or stop making articles like this) |
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An '''open set''' in [[Euclidean space]] is a [[set]] that contains a [[ball (mathematics)]] around each of its points.{{fact}} In Euclidean space, a "ball" of radius ''r'' centered at a point ''p'' is the set of all points which are distance at most ''r'' from ''p''. Intuitively, if a point is contained in an open set, then all points sufficiently close to it are also contained. | An '''open set''' in [[Euclidean space]] is a [[set]] that contains a [[ball (mathematics)]] around each of its points.{{fact}} In Euclidean space, a "ball" of radius ''r'' centered at a point ''p'' is the set of all points which are distance at most ''r'' from ''p''. Intuitively, if a point is contained in an open set, then all points sufficiently close to it are also contained. | ||
Revision as of 01:44, August 31, 2008
Template:Esoteric An open set in Euclidean space is a set that contains a ball (mathematics) around each of its points.[Citation Needed] In Euclidean space, a "ball" of radius r centered at a point p is the set of all points which are distance at most r from p. Intuitively, if a point is contained in an open set, then all points sufficiently close to it are also contained.
Open sets are the basic objects in topology, in terms of which all other objects are defined.