Khan Academy Static

A parabola is the set of all points equidistant from a point (called the focus) and a line (called the directrix). In this tutorial you will learn about the focus and the directrix, and how to find the equation of a parabola given its focus and directrix.

2675_Intro_to_focus_directrix.html

2677_Focus_directrix_of_a_parabola_from_equation_.html

2676_Equation_of_a_parabola_from_focus_directrix.html