Parabola
The parabola is the locus of points on the plane that is equidistant from a fixed point called the focus and a fixed line called the directrix.
Elements of the Parabola
Focus
The focus is the fixed point F.
Directrix
The directrix is the fixed line d.
Focal Parameter
The focal parameter is the distance from the focus to the directrix. It is denoted by p.
Axis
The axis is the line perpendicular to the directrix that passes through the focus.
Vertex
The vertex is the point of intersection of the parabola with its axis.
