Quadratic Function Point Plotting with Vertex Method

This example demonstrates how to draw a parabola for a quadratic function using the point-plotting (描点法) / vertex method (顶点法). It emphasizes locating key points—especially the vertex and symmetry-related points—so the graph can be completed accurately. The main mathematical ideas are quadratic-function graph properties, the vertex and axis of symmetry, determining the parabola from essential points, and related geometric visualization (including tangent-line/“tangent” style annotations). Construction highlights from the provided GeoGebra commands include: Textfield for interactive parameter input and labeling; Segment for building connecting auxiliary segments between constructed points; and Translate to create translated points/lines that support symmetry or reusable geometric constructions. Input box objects drive the computed points, while multiple text label objects (with suffixes) are used to display intermediate results clearly. Suitable for middle to high school function instruction, graphing practice, and GeoGebra-based geometry construction learning.