a plane curve formed by the intersection of a right circular cone with a plane parallel to a generator of the cone; the set of points in a plane that are equidistant from a fixed line and a fixed point in the same plane or in a parallel plane. Equation: y 2 = 2 px or x 2 = 2 py.

a conic section formed by the intersection of a cone by a plane parallel to its side. Standard equation: y² = 4ax, where 2a is the distance between focus and directrix