Witch of Agnesi

A bell-shaped cubic drawn from a circle: a line from O meets the circle at one point and the tangent opposite O at another, and the curve takes its height from the first and its width from the second. Its English name comes from John Colson, who read Agnesi’s Italian name for it, versiera, as witch. It is also the density curve of the Cauchy distribution.

y = 8a³/(x² + 4a²)

On mathcurve.com as Cubique d’Agnesi