Investigating Limits Informally: A Visual Approach

① This GeoGebra example demonstrates the informal concept of limits by showing how function values approach a target as the input approaches a point, using dynamic visual feedback. ② Core mathematical concepts include limits (two-sided and one-sided), continuity, and the behavior of sequences of points on the real number line. ③ Construction details: Based on the summary, it uses Point and Vector commands, creating objects such as function f, dynamic points A, P, Q, B, C, D, E, and text labels (text1, text2, text3) to display numerical values; users can drag points to observe how function values change and approach a limit. ④ Suitable for high school seniors or early university students learning calculus, as an introductory or review tool for limit concepts, and for teachers to demonstrate the intuitive meaning of limits through numerical and graphical exploration.