In this post we review the concept of a elementary arithmetic done with vectors and matrices, both of which are often referred to as arrays.

Here we explain general linear functions and their relationship to matrices. We spend considerable time discussing the special case of the square matrix, for which we describe the important topics of eigenvectors and eigenvalues.

In this post we discuss popular vector and mtrix norms that will arise frequently in our study of machine learning and deep learning. A norm is a kind of function that measures the length of real vectors and matrices. The notion of length is extremely useful as it enables us to define distance - or similarity - between any two vectors (or matrices) living in the same space.