There are three forms this shape can take, one of which includes a loop and another one of which is a cardioid.
Starting with a circle and fixed point P, this curve is the locus of all points X so that PX is perpendicular to a tangent line of the circle, which means that this is the pedal [PEED-ul] curve of a circle. Similar to a hypocycloid [hie-poe-SIE-kloid], this can be generated by following a point inside one circle as that circle rolls around outside another circle. There are three forms this shape can take, one of which includes a loop and another one of which is a cardioid. Name this shape generated by the equation r equals c plus d sine theta.
Starting with a circle and fixed point P, this curve is the locus of all points X so that PX is perpendicular to a tangent line of the circle, which means that this is the pedal [PEED-ul] curve of a circle.
limacon