# parabola

[puh-rab-uh-luh]

- a plane curve formed by the intersection of a right circular cone with a plane parallel to a generator of the cone; the set of points in a plane that are equidistant from a fixed line and a fixed point in the same plane or in a parallel plane. Equation: y2 = 2px or x2 = 2py.

## Origin of parabola^{}

Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

## Examples from the Web for parabola

### Historical Examples

#### He reached the height of the 'parabola,' and is now about to descend.

Debts of HonorMaurus Jkai

#### Is the orbit that of an ellipse, or a circle, or a parabola?

Aether and GravitationWilliam George Hooper

#### You will remember that a Republican State is represented by a parabola.

The Romance of MathematicsP. Hampson

#### Its actual path will be a curve, which in this case is a parabola.

Pioneers of ScienceOliver Lodge

#### As a matter of fact the path of a projectile in vacuo is only approximately a parabola.

Pioneers of ScienceOliver Lodge

# parabola

- a conic section formed by the intersection of a cone by a plane parallel to its side. Standard equation: y ² = 4 ax, where 2 a is the distance between focus and directrix

## Word Origin

C16: via New Latin from Greek parabolē a setting alongside; see parable

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

## Word Origin and History for parabola

### n.

1570s, from Modern Latin parabola, from Greek parabole "parabola, comparison, analogy; application" (see parable), so called by Apollonius of Perga c.210 B.C.E. because it is produced by "application" of a given area to a given straight line. It had a different sense in Pythagorean geometry. Related: Parabolic.

Online Etymology Dictionary, © 2010 Douglas Harper

# parabola

[pə-răb′ə-lə]

- The curve formed by the set of points in a plane that are all equally distant from both a given line (called the directrix) and a given point (called the focus) that is not on the line.

The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

# parabola

[(puh-rab-uh-luh)]

## Note

The New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.