Wolfram Demonstrations Projecthttp://demonstrations.wolfram.com/An Open Resource of Interactive Mathematica VisualizationsCopyright 2009 Wolfram Demonstrations Project & ContributorsConic Sections: Equations and Graphshttp://demonstrations.wolfram.com/ConicSectionsEquationsAndGraphs/]]>http://demonstrations.wolfram.com/ConicSectionsEquationsAndGraphs/