Pedals and inversions of quadratic curves

Abstract

The pedal of a curve in the Euclidean plane is a classical subject which has a singular point at the inflection point of the original curve or the pedal point. The primitive of a curve is a curve given by the inverse construction for making the pedal. In this paper we consider the pedal of a quadratic curve. On of the main results gives a characterization of such curves, which is one of the generalizations of limacons of Pascal.