Negative Pedal Curves of an Ellipse

a

b

pedal

origin

focus

The pedal curve of a curve

C

with respect to a point

P

is the curve whose points are the closest to

P

on the tangents of

C

. This Demonstration concerns the inverse of a pedal curve, sometimes called the negative pedal curve. The negative pedal of a curve

C

can be defined as a curve

C'

such that the pedal of

C

is

C'

. This Demonstration allows you to explore two sets of the negative pedal curves of an ellipse.