Span of Vectors in R^3

This example demonstrates the span of two vectors u and v in three-dimensional space, dynamically visualizing the plane they form. Core math concepts include vectors, vector spaces, and plane geometry. Construction involves using Textfield for annotations, Plane to define the plane, InputBox1 and InputBox2 for vector inputs, points A, B, C on the plane, and variable a for assistance. Suitable for high school and above students studying vector spaces, linear algebra, and 3D geometry.