Parabolic spiral
Parabolic Par`a*bol"ic, Parabolical Par`a*bol"ic*al, a. [Gr. paraboliko`s figurative: cf. F. parabolique. See {Parable}.] [1913 Webster] 1. Of the nature of a parable; expressed by a parable or figure; allegorical; as, parabolical instruction. [1913 Webster]

2. [From {Parabola}.] (Geom.) (a) Having the form or nature of a parabola; pertaining to, or resembling, a parabola; as, a parabolic curve. (b) Having a form like that generated by the revolution of a parabola, or by a line that moves on a parabola as a directing curve; as, a parabolic conoid; a parabolic reflector; a parabolic antenna. [1913 Webster +PJC]

{Parabolic conoid}, a paraboloid; a conoid whose directing curve is a parabola. See {Conoid}.

{Parabolic mirror} (Opt.), a mirror having a paraboloidal surface which gives for parallel rays (as those from very distant objects) images free from aberration. It is used in reflecting telescopes.

{Parabolic spindle}, the solid generated by revolving the portion of a parabola cut off by a line drawn at right angles to the axis of the curve, about that line as an axis.

{Parabolic spiral}, a spiral curve conceived to be formed by the periphery of a semiparabola when its axis is wrapped about a circle; also, any other spiral curve having an analogy to the parabola. [1913 Webster]


The Collaborative International Dictionary of English. 2000.

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  • Parabolic — Par a*bol ic, Parabolical Par a*bol ic*al, a. [Gr. paraboliko s figurative: cf. F. parabolique. See {Parable}.] [1913 Webster] 1. Of the nature of a parable; expressed by a parable or figure; allegorical; as, parabolical instruction. [1913… …   The Collaborative International Dictionary of English

  • Parabolic conoid — Parabolic Par a*bol ic, Parabolical Par a*bol ic*al, a. [Gr. paraboliko s figurative: cf. F. parabolique. See {Parable}.] [1913 Webster] 1. Of the nature of a parable; expressed by a parable or figure; allegorical; as, parabolical instruction.… …   The Collaborative International Dictionary of English

  • Parabolic mirror — Parabolic Par a*bol ic, Parabolical Par a*bol ic*al, a. [Gr. paraboliko s figurative: cf. F. parabolique. See {Parable}.] [1913 Webster] 1. Of the nature of a parable; expressed by a parable or figure; allegorical; as, parabolical instruction.… …   The Collaborative International Dictionary of English

  • Parabolic spindle — Parabolic Par a*bol ic, Parabolical Par a*bol ic*al, a. [Gr. paraboliko s figurative: cf. F. parabolique. See {Parable}.] [1913 Webster] 1. Of the nature of a parable; expressed by a parable or figure; allegorical; as, parabolical instruction.… …   The Collaborative International Dictionary of English

  • Fermat's spiral — (also known as a parabolic spiral) follows the equation:r = pm heta^{1/2},in polar coordinates (the more general Fermat s spiral follows r 2 = a 2 theta; .) It is a type of Archimedean spiral. [mathworld|urlname=FermatsSpiral |title=Fermat… …   Wikipedia

  • Parabolical — Parabolic Par a*bol ic, Parabolical Par a*bol ic*al, a. [Gr. paraboliko s figurative: cf. F. parabolique. See {Parable}.] [1913 Webster] 1. Of the nature of a parable; expressed by a parable or figure; allegorical; as, parabolical instruction.… …   The Collaborative International Dictionary of English

  • Helicoid — Hel i*coid, a. [Gr. ?; ?, ?, spiral + ? shape: cf. F. h[ e]lico[ i]de. See {Helix}.] [1913 Webster] 1. Spiral; curved, like the spire of a univalve shell. [1913 Webster] 2. (Zo[ o]l.) Shaped like a snail shell; pertaining to the {Helicid[ae]}, or …   The Collaborative International Dictionary of English

  • Helicoid parabola — Helicoid Hel i*coid, a. [Gr. ?; ?, ?, spiral + ? shape: cf. F. h[ e]lico[ i]de. See {Helix}.] [1913 Webster] 1. Spiral; curved, like the spire of a univalve shell. [1913 Webster] 2. (Zo[ o]l.) Shaped like a snail shell; pertaining to the… …   The Collaborative International Dictionary of English

  • Möbius transformation — Not to be confused with Möbius transform or Möbius function. In geometry, a Möbius transformation of the plane is a rational function of the form of one complex variable z; here the coefficients a, b, c, d are complex numbers satisfying ad − …   Wikipedia

  • Polar coordinate system — Points in the polar coordinate system with pole O and polar axis L. In green, the point with radial coordinate 3 and angular coordinate 60 …   Wikipedia

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