# Definition of *conchoid* in English:

## conchoid

Syllabification: con·choidPronunciation: /ˈkäNGˌkoid
/

### noun

*Mathematics*

- A plane quartic curve consisting of two separate branches either side of and asymptotic to a central straight line (the asymptote), such that if a line is drawn from a fixed point (the pole) to intersect both branches, the part of the line falling between the two branches is of constant length and is exactly bisected by the asymptote.
- Such curves are represented by the general equation (
*x*-*a*)^{2}(*x*^{2}+*y*^{2}) =*b*^{2}*x*^{2}, where*a*is the distance between the pole and the asymptote, and*b*is the constant length. The branch on the same side of the asymptote as the pole typically has a cusp or loop

More example sentences- Nicomedes is famous for his treatise On conchoid lines which contain his discovery of the curve known as the conchoid of Nicomedes.
- The ruler has a fixed distance marked on it and one mark is kept on a given line while the other traces the conchoid curve.
- Nicomedes, who was highly critical of Eratosthenes' mechanical solution, gave a construction which used the conchoid curve which he also used to solve the problem of trisection of an angle.

- Such curves are represented by the general equation (