Parabola Focus and Directrix Dynamic Demonstration

This GeoGebra example dynamically demonstrates the focus-directrix definition of a parabola: every point on the parabola is equidistant from the focus and the directrix. Core mathematical concepts include conic sections, focus, directrix, axis of symmetry, and geometric locus. Construction details: the Line command creates the directrix, OrthogonalLine constructs perpendiculars, Intersect finds intersection points, Segment connects points, Midpoint determines the vertex, Point marks the focus and a moving point, and Angle displays relevant angles. By dragging the moving point, students can visually verify the equal-distance property. Suitable for middle or high school analytic geometry lessons, helping learners grasp the geometric essence of parabolas.