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Parabola

A u-shaped curve with certain specific properties. Formally, a parabola is defined as follows: For a given point, called the focus, and a given line not through the focus, called the directrix, a parabola is the locus of points such that the distance to the focus equals the distance to the directrix.

Note: It is a common error to call any u-shaped curve a parabola. A parabola must satisfy the conditions listed above, and a parabola always has a quadratic equation.

 

 

Example:  

This is a graph of the parabola with all its major features labeled: axis of symmetry, focus, vertex, and directrix.

 

See also

Area of a parabolic segment, focal radius

 


  this page updated 19-jul-17
Mathwords: Terms and Formulas from Algebra I to Calculus
written, illustrated, and webmastered by Bruce Simmons
Copyright © 2000 by Bruce Simmons
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