# Mathematics 221. Linear Algebra

How might you draw a 3D image on a 2D screen and then "rotate" it? What are the basic notions behind Google's original, stupefyingly efficient search engine? After measuring the interacting components of a nation's economy, can one find an equilibrium? Starting with a simple graph of two lines and their equations, we develop a theory for systems of linear equations that answers questions like those posed here. This theory leads to the study of matrices, vectors, linear transformations and geometric properties for all of the above. We learn what "perpendicular" means in high-dimensional spaces and what "stable" means when transforming one linear space into another. Topics also include: matrix algebra, determinants, eigenspaces, orthogonal projections and a theory of vector spaces.