Conic Sections - Parabola
- Tobias Teo
This applet demonstrates the focus-directrix definition of a parabola, that is: A parabola is the locus of a point P in a plane such that the distance between P and the focus F is equal to the distance between P and the directrix. In other words, if M is the foot of the perpendicular from P to the directrix, then
PF = PM.
How to use the applet: Click on the buttons in the top row to see the following parabolas:
- y2 = 4ax - Focus (a,0), directrix x = -a
- x2 = 4ay - Focus (0,a), directrix y = -a