Practical Vector Calculus for the AI Era
This blog presents undergraduate-level vector calculus with examples and perspectives drawn from artificial intelligence. It was created in response to the limitations of many existing calculus textbooks in addressing the conceptual demands of this rapidly evolving field. Before we begin, it is important to clarify how the variable \(\mathbf{x}\) will be used throughout the text. In classical calculus, the variable \(\mathbf{x}\) typically denotes a physical coordinate, such as position in space. In deep learning, however, \(\mathbf{x}\) often represents a token or a feature vector that encodes complex structures, including language, images, or speech. This shift reflects a transition from modeling physical space to modeling abstract, high-dimensional data spaces. 1. Vectors Vectors are mathematical entities characterized by both magnitude and direction. They are essential for describing physical quantities such as blood flow velocity, forces acting on joints, an...