witch of Agnesiwitch of Ag·ne·si
A planar cubic curve that is symmetric about the y-axis and that approaches the x-axis as an asymptote. Its equation is x2y = 4a2(2a − y), where a is a constant.
Origin of witch of Agnesiwitch (translation of Italian avversiera, versiera, confused with versiera, curve, turning, from New Latin vers&omacron;ria, from Latin versus, turned, reversed, past participle of vertere, to turn; see verse1) + Maria Gaetana Agnesi.
witch of Agnesi
A segment drawn from the origin to A intersects a circle of radius a at B. The witch of Agnesi is the curve formed by P as A moves along the line C.