Function Graph Plotting

This example demonstrates how to plot a function graph in GeoGebra, representing a function RP^1 -> RP^1 as a subset of S^1 x S^1 (circle). Key math concepts include functions, Cartesian products, parametric equations, and analytical geometry. Construction highlights the use of commands like Surface, CurveCartesian, and Textfield with objects such as function f, circle R, parameter r, point a, graph_f, auxiliary point g, X-axis, origin O_{0,0}, point at infinity P_{(∞,∞)}, and inputBox1. Suitable for high school and above students to learn function graph plotting techniques, ideal for mathematical instruction and geometric visualization understanding.