The curve with implicit equation
References
Gray, A. Modern Differential Geometry of Curves and Surfaces. Boca Raton, FL: CRC Press, pp. 71-72, 1993.
![\begin{displaymath}[(x-b)^2+y^2][x(x-b)+y^2]-4a(x-b)y^2.
\end{displaymath}](k_390.gif){kind=small}