Definition of Derivative - Task 4: Interactive Exploration of Tangent Slope and

This GeoGebra example dynamically illustrates the definition of the derivative as the slope of the tangent line to a function at a point. The core mathematical concept is the limit definition of the derivative: as the increment h approaches zero, the slope of the secant line approaches the slope of the tangent line. The construction uses Textfield and InputBox for user input, If for conditional logic, Tangent to generate the tangent line, Line and Polygon for auxiliary shapes, and sliders (a, h) to control dynamic changes. It is suitable for high school or introductory college calculus students to grasp the geometric meaning of the derivative and the limiting process from secant to tangent.