parabola

parabola (pərăbˈələ) [key], plane curve consisting of all points equidistant from a given fixed point (focus) and a given fixed line (directrix). It is the conic section cut by a plane parallel to one of the elements of the cone. The axis of a parabola is the line through the focus perpendicular to the directrix. The vertex is the point at which the axis intersects the curve. The latus rectum is the chord through the focus perpendicular to the axis. Examples of this curve are the path of a projectile and the shape of the cross section of a parallel beam reflector.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

More on parabola from Fact Monster:

  • Apollonius of Perga - Apollonius of Perga Apollonius of Perga, fl. 247–205 B.C., Greek mathematician of the ...
  • conic section - conic section conic section or conic, curve formed by the intersection of a plane and a right ...
  • orbit: Nonplanetary Orbits - Nonplanetary Orbits The laws of planetary orbits also apply to the orbits of comets, natural ...
  • curve - curve curve, in mathematics, a line no part of which is straight; more generally, it is considered ...
  • cylinder - cylinder cylinder, in mathematics, surface generated by a line moving parallel to a given fixed ...

See more Encyclopedia articles on: Mathematics