Geometric Construction of Parabola: Locus and Secant Method

This example demonstrates how to construct a parabola using geometric construction methods. Core mathematical concepts include the locus definition of parabola, the relationship between focus and directrix, and the limiting relationship between secant and tangent lines. Construction key points extracted from GeoGebra commands: Using Line, Point, OrthogonalLine to draw the directrix and perpendicular from focus; using LineBisector to find the midpoint locus between focus and moving point; using Intersect to determine intersection points; finally generating parabola loc1 through Locus command, with objects including points A, B, C, D, E and lines a, b, c, d. Suitable for high school mathematics, analytic geometry courses, math competitions, and geometry construction enthusiasts.