## witch of Agnesi

witch of Ag·ne·sinoun

A planar cubic curve that is symmetric about the

*y*-axis and that approaches the*x*-axis as an asymptote. Its equation is*x*^{2}*y*= 4*a*^{2}(2*a*−*y*), where*a*is a constant.Origin of witch of Agnesi

**witch**(

*translation of*Italian

*avversiera, versiera*) (

*confused with*

*versiera*

*curve, turning*) (

*from*New Latin

*versōria*) (

*from*Latin

*versus*

*turned, reversed*) (

*past participle of*

*vertere*

*to turn*; see

**verse**

^{1}. )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.