Deltoid Table of Contents Deltoid Deltoid and its Tangents Mathematica Notebook for This Page . History Conceived by Euler in 1745 in connection with a study of caustics curves. The latter is called double generation. The right figure shows the coordination of both methods.
P is the tracing point.
OHCJ are colinear. JPT are colinear. Let a be a scaling factor, and a is the distance from deltoid's center to a cusp. A be the center of the curve. Let B be one cusp, P be any point on the curve.