Adjacent Words

conic section definitions

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WordNet (r) 3.0 (2005)

n
1: (geometry) a curve generated by the intersection of a plane and a circular cone [syn: conic section, conic]

Merriam Webster's

noun Date: 1664 1. a plane curve, line, pair of intersecting lines, or point that is the intersection of or bounds the intersection of a plane and a cone with two nappes 2. a curve generated by a point which always moves so that the ratio of its distance from a fixed point to its distance from a fixed line is constant

Britannica Concise

Any two-dimensional curve traced by the intersection of a right circular cone with a plane. If the plane is perpendicular to the cone's axis, the resulting curve is a circle. Intersections at other angles result in ellipses, parabolas, and hyperbolas. The conic sections are studied in Euclidean geometry to analyze their physical properties and in coordinate geometry to derive their equations. In either context, they have useful applications to optics, antenna design, structural engineering, and architecture.

Webster's 1913 Dictionary

Conic Con"ic, Conical Con"ic*al, a. [Gr. ?: cf. F. conique. See Cone.] 1. Having the form of, or resembling, a geometrical cone; round and tapering to a point, or gradually lessening in circumference; as, a conic or conical figure; a conical vessel. 2. Of or pertaining to a cone; as, conic sections. Conic section (Geom.), a curved line formed by the intersection of the surface of a right cone and a plane. The conic sections are the parabola, ellipse, and hyperbola. The right lines and the circle which result from certain positions of the plane are sometimes, though not generally included. Conic sections, that branch of geometry which treats of the parabola, ellipse, and hyperbola. Conical pendulum. See Pendulum. Conical projection, a method of delineating the surface of a sphere upon a plane surface as if projected upon the surface of a cone; -- much used by makers of maps in Europe. Conical surface (Geom.), a surface described by a right line moving along any curve and always passing through a fixed point that is not in the plane of that curve.