Let be a curve and let be a fixed point. Let be on and let be the Curvature Center at . Let be the point with a line segment Parallel and of equal length to . Then the curve traced by is the radial curve of . It was studied by Robert Tucker in 1864. The parametric equations of a curve with Radial Point are

 Curve Radial Curve Astroid Quadrifolium Catenary Kampyle of Eudoxus Cycloid Circle Deltoid Trifolium Logarithmic Spiral Logarithmic Spiral Tractrix Kappa Curve

References

Lawrence, J. D. A Catalog of Special Plane Curves. New York: Dover, pp. 40 and 202, 1972.

Yates, R. C. Radial Curves.'' A Handbook on Curves and Their Properties. Ann Arbor, MI: J. W. Edwards, pp. 172-174, 1952.