The Umbracle in Valencia, Spain

The definition of a parabola is a symmetrical plane curve that forms when a cone intersects with a plane parallel to its side.

A u-shaped graph of a quadratic function is an example of a parabola.

## parabola

Geom. a plane curve which is the path, or locus, of a moving point that remains equally distant from a fixed point (

*focus*) and from a fixed straight line (*directrix*); curve formed by the section of a cone cut by a plane parallel to the side of the coneOrigin of parabola

Modern Latin ; from Classical Greek*parabol?,*literally , application, comparison (see parable): it is produced by the “application” of a given area to a given straight line

## parabola

noun

A plane curve formed by the intersection of a right circular cone and a plane parallel to an element of the cone or by the locus of points equidistant from a fixed line and a fixed point not on the line.

Origin of parabola

New Latin, from Greek*parabol&emacron;*,

*comparison, application, parabola (from the relationship between the line joining the vertices of a conic and the line through its focus and parallel to its directrix)*, from

*paraballein*,

*to compare*; see

**parable**.

**parabola**

Any point on a parabola is the same distance from the directrix as it is from the focus (F). AC equals CF and BD equals DF.

## parabola

Noun

(*plural* parabolas *or* parabolae *or* parabolÃ¦)

- (geometry) The conic section formed by the intersection of a cone with a plane parallel to a tangent plane to the cone; the locus of points equidistant from a fixed point (the focus) and line (the directrix).
- (rhetoric) The explicit drawing of a parallel between two essentially dissimilar things, especially with a moral or didactic purpose. A parable.

Origin

From Ancient Greek *Ï€Î±ÏÎ±Î²Î¿Î»Î®* (parabolÄ“), from *Ï€Î±ÏÎ±Î²Î¬Î»Î»Ï‰* (paraballÅ, “I set side by side"), from *Ï€Î±ÏÎ¬* (para, “beside") + *Î²Î¬Î»Î»Ï‰* (ballÅ, “I throw").