PLANE CURVES A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site epicycloid The path traced out by a point on the circumference of a circle of radius b rolling on the outside of a circle of radius a. It is described by the parametric equations:       x = (a + b) cos(t) - b cos[(a/b + 1)t],       y = (a + b) sin(t) - b sin[(a/b + 1)t]. An epicycloid is like a cycloid on the circumference of a circle and is closely related to the epitrochoid, hypocycloid, and hypotrochoid. An epicycloid with one cusp is called a cardioid, one with two cusps is called a nephroid, and one with five cusps is called a ranunculoid (after the buttercup genus Ranunculus). Related category    • PLANE CURVES Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP