PEDAL CURVE : Summary

If you have worked through the pedal curve constructions, you will have discovered the results in the following table. We have only listed the cases where the pedal curve is known or of interest.

CURVES AND THEIR PEDAL CURVES
Original curve 
Pedal point
Pedal curve

Astroid

Centre
Quadrifolium 

Cardioid

Cusp 
Cayley’s sextic 

Circle

Any point not at centre
Limaçon

Circle

On circle
Cardioid

Deltoid

 Cusp
Simple folium 

Deltoid

Vertex
Regular bifolium

Deltoid

Centre
Trifolium

Ellipse

Focus
Circle 

Hyperbola

Focus
Circle  

Rectangular hyperbola

Centre
Lemniscate

Parabola

Focus 
Line 

Parabola

Vertex 
Cissoid 

Parabola

Intersection of directrix and axis
Right strophoid

Parabola

Reflection of focus in directrix
Trisectrix of Maclaurin