3D Contour and Level Curves Demo

This example demonstrates the intersection of 3D surfaces with 2D planes to form contour or level curves, highlighting spatial geometry, function graphs, derivatives, and gradient concepts. It uses GeoGebra commands like Textfield and IntersectPath with objects such as a, d, d_1, b, boundaries, and parameters to create interactive visualizations. Suitable for high school students and educators exploring calculus and solid geometry.