Linear Regression Is Actually a Projection Problem, Part 1: The Geometric Intuition

Linear regression can be understood from a geometric perspective as a vector projection problem. The content first demonstrates a standard linear regression model using Python and scikit-learn to establish a baseline. It then shifts focus to building the necessary mathematical foundation, starting with a review of vectors, their magnitude, and direction. The dot product is explained in detail, showing how it measures the agreement between two vectors and relates to the angle between them. This foundational knowledge is presented as a prerequisite for understanding vector projections, which will be used to solve the linear regression problem in a subsequent part.