Root Form from Graph

Root Form from Graph
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2016-02-14 05:45
This GeoGebra example demonstrates how to derive the root form (factored form) of a quadratic function directly from its graph by reading the two x-intercepts (roots) and the y-intercept. The core mathematical concepts include the factored form of quadratics, the relationship between roots and coefficients, the axis of symmetry, and the vertex coordinates. Construction details: the Random command generates random parameters, Intersect finds the roots (Root_1, Root_2) and the y-intercept, Extremum locates the vertex (TP), and the axis of symmetry (LoS) is drawn. A ShowAnswers toggle reveals the final equation for self-checking. This is suitable for middle or high school students learning to convert between graphical and algebraic representations of quadratic functions, either in classroom demonstrations or independent practice.

GeoGebra Commands & Parameters

  1. Random(-5, 5) → m
  2. Random(-5, 5) → n
  3. Intersect(c, xAxis, 2) → Root_1
  4. Intersect(c, xAxis, 1) → Root_2
  5. Intersect(c, yAxis, 1) → yintercept
  6. Extremum(((x + m) * (x + n))) → TP