conchoid

[kong-koid]

noun Geometry.

a plane curve such that if a straight line is drawn from a certain fixed point, called the pole of the curve, to the curve, the part of the line intersected between the curve and its asymptote is always equal to a fixed distance. Equation: r = b ± a sec(θ).

Origin of conchoid

From the Greek word konchoeidḗs, dating back to 1790–1800. See conch, -oid

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Examples from the Web for conchoid

Historical Examples of conchoid

Conchoid′al, pertaining to a conchoid: shell-like, applied to the fracture of a mineral; Concholog′ical, pertaining to conchology.
Chambers's Twentieth Century Dictionary (part 1 of 4: A-D)
Various
The conchoid has been employed by later mathematicians, notably Sir Isaac Newton, in the construction of various cubic curves.
Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 7
Various

British Dictionary definitions for conchoid

conchoid

noun

geometry a plane curve consisting of two branches situated about a line to which they are asymptotic, so that a line from a fixed point (the pole) intersecting both branches is of constant length between asymptote and either branch. Equation: (x – a)²(x ² + y ²) = b ² x ² where a is the distance between the pole and a vertical asymptote and b is the length of the constant segment

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