conchoid (con|choid)

noun

• 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(x² + y²) = b²x², 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