Parabola - conic definition

Author:
Vera Hu
Topic:
Parabola
Move the point D on the directrix, what do you see? Now, move the Focus, what will happen with the graph, compare with the original. You want to move Focus up down, right left. Tell me what do you observed. Move the Directrix up or down, observe the change of graph.
Vera Hu-Hyneman, Suffolk County Community College