conchoid
[kongkoid]

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
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Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
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Historical Examples of conchoid
Conchoid′al, pertaining to a conchoid: shelllike, applied to the fracture of a mineral; Concholog′ical, pertaining to conchology.
The conchoid has been employed by later mathematicians, notably Sir Isaac Newton, in the construction of various cubic curves.
conchoid
noun
Collins English Dictionary  Complete & Unabridged 2012 Digital Edition
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