Secant Line Activity on a Parabola

This GeoGebra example demonstrates a secant line drawn through two points on a parabola, dynamically showing how the secant slope changes as the points move and illustrating the limiting relationship between secants and tangents. Core mathematical concepts include parabolas, quadratic functions, coordinate geometry, secant slope computation, and the geometric meaning of the derivative as the limit of secant slopes. Construction highlights, drawn from the provided command summary, involve GeoGebra commands Textfield, Line, and Slope, together with objects c, s, inputBox1, t, A, h, v, w, B, a, m; points A and B determine the secant’s intersections, parameter h controls horizontal shift, inputBox1 and t enable interactive input, line c represents the secant, and slope s displays its inclination in real time. The resource is suitable for high school mathematics covering functions and derivatives, as well as introductory university calculus visualization, classroom inquiry, and independent student exploration.