A _____ is the set of all points in a plane that are equidistant from a fixed line and a fixed point in the plane.
Dear student. A parabola is "the set of all points in a plane equidistant from a fixed point (focus) and a fixed line (directrix)". The distances to any point (x,y) on the parabola from the focus (0,p) and the directrix y=-p, are equal to each other. This can be used to develop the equation of a parabola. Regards