Origin of conchoid

from Classical Greek*konchoeid?s*

*(gramm?)*, conchoid (line), literally , mussel-like: see conch and -oid

a curve traced by an end point of a segment of constant length located on a straight line that rotates about a fixed point, while the other end point moves along a straight line that does not go through the fixed point

Origin of conchoid

from Classical GreekWebster's New World College Dictionary, Fifth Edition Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

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"conchoid." YourDictionary, n.d. Web. 18 December 2018. <https://www.yourdictionary.com/conchoid>.

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conchoid. (n.d.). Retrieved December 18th, 2018, from https://www.yourdictionary.com/conchoid

Noun

(*plural* conchoids)

- (mathematics) Any of a family of curves defined as the locus of a point,
*P*, on a line from a given fixed point to a given curve,*C*, where the distance along the line from*C*to*P*remains constant.*The conchoid of a circle with respect to a point on the circle is a cardioid if the fixed distance is equal to the diameter of the circle.**The Conchoid of Nicomedes is the conchoid of a straight line with respect to a point not on the line.*

English Wiktionary. Available under CC-BY-SA license.

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**MLA Style**

"conchoid." YourDictionary, n.d. Web. 18 December 2018. <https://www.yourdictionary.com/conchoid>.

**APA Style**

conchoid. (n.d.). Retrieved December 18th, 2018, from https://www.yourdictionary.com/conchoid

- Thus Nicomedes invented the
**conchoid**; Diodes the cissoid; Dinostratus studied the quadratrix invented by Hippias; all these curves furnished solutions, as is also the case with the trisectrix, a special form of Pascal's limacon. - Pappus turns then to a consideration of certain properties of Archimedes's spiral, the
**conchoid**of Nicomedes (already mentioned in book i. - The Greek geometers invented other curves; in particular, the
**conchoid**, which is the locus of a point such that its distance from a given line, measured along the line drawn through it to a fixed point, is constant; and the cissoid, which is the locus of a point such that its distance from a fixed point is always equal to the intercept (on the line through the fixed point) between a circle passing through the fixed point and the tangent to the circle at the point opposite to the fixed point.