Parabolas

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Parabola \Pa*rab"o*la\, n.; pl. {Parabolas}. [NL., fr. Gr. ?; --
     so called because its axis is parallel to the side of the
     cone. See {Parable}, and cf. {Parabole}.] (Geom.)
     (a) A kind of curve; one of the conic sections formed by the
         intersection of the surface of a cone with a plane
         parallel to one of its sides. It is a curve, any point of


         which is equally distant from a fixed point, called the
         focus, and a fixed straight line, called the directrix.
         See {Focus}.
     (b) One of a group of curves defined by the equation y =
         ax^{n} where n is a positive whole number or a positive
         fraction. For the {cubical parabola} n = 3; for the
         {semicubical parabola} n = 3/2. See under {Cubical}, and
         {Semicubical}. The parabolas have infinite branches, but
         no rectilineal asymptotes.
         [1913 Webster]