The pedal curve of an ellipse with parametric equations

			(1)
			(2)

and pedal point is given by

			(3)
			(4)

The pedal curve of an ellipse with pedal point at the focus is a circle (Hilbert and Cohn-Vossen 1999, pp. 25-26).

For other pedal points, the pedal curves are more complicated, as illustrated above.

Ameseder, A. "Ueber Fusspunktcurven der Kegelschnitte." Archiv Math. u. Phys. 64, 143-144, 1879.

Ameseder, A. "Zur Theorie der Fusspunktencurven der Kegelschnitte." Archiv Math. u. Phys. 64, 145-163, 1879.

Hilbert, D. and Cohn-Vossen, S. Geometry and the Imagination. New York: Chelsea, 1999.

CITE THIS AS:

Weisstein, Eric W. "Ellipse Pedal Curve." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/EllipsePedalCurve.html