Introduction to Linear Algebra

Chapter 1: Foundations

What is a Vector?

Introduction to vectors as arrows and lists of numbers.
Requirements: Basic Algebra Difficulty: 1

Vector Addition

How to add vectors geometrically and algebraically.
Requirements: Vectors Difficulty: 1

Linear Combinations

The fundamental building block of linear algebra.
Requirements: Vectors Difficulty: 2

What is Span?

Understanding the space reachable by a set of vectors.
Requirements: Linear Combinations Difficulty: 2

Linear Independence

Why some vectors are "redundant" in a set.
Requirements: Span Difficulty: 2

Basis of a Vector Space

The set of vectors that perfectly describe a space.
Requirements: Independence Difficulty: 3

Dimension Explained

Why we call a line 1D and a plane 2D.
Requirements: Basis Difficulty: 2

Chapter 2: Matrices

Introduction to Matrices

Thinking of matrices as data structures.
Requirements: Basic Algebra Difficulty: 1

Matrix-Vector Product

The first step toward linear transformations.
Requirements: Vector Operations Difficulty: 2

Matrix Multiplication

How to combine two matrix transforms into one.
Requirements: Matrix-Vector Product Difficulty: 2

The Identity Matrix

The "Number 1" of the matrix world.
Requirements: Matrix Mult. Difficulty: 1

The Transpose

Flipping a matrix across its diagonal.
Requirements: Intro to Matrices Difficulty: 2

The Inverse Matrix

How to "undo" a linear transformation.
Requirements: Determinants Difficulty: 3

Chapter 3: Transformations

Linear Transformations

Viewing matrices as actions/functions on space.
Requirements: Matrix-Vector Product Difficulty: 3

Rotations and Scaling

Using matrices to spin and stretch 2D objects.
Requirements: Linear Transf. Difficulty: 3

Shear Transformations

Distorting space while keeping lines parallel.
Requirements: Linear Transf. Difficulty: 3

Composition of Transformations

Applying multiple matrices in sequence.
Requirements: Matrix Mult. Difficulty: 3

Determinants - The Area Factor

How matrices change the size of shapes.
Requirements: Linear Transf. Difficulty: 3

Affine Transformations

Adding translations to our toolkit
Requirements: Linear Transf. Difficulty: 3

Chapter 4: Linear Systems

Systems of Linear Equations

Intersecting lines and planes.
Requirements: Basic Algebra Difficulty: 1

Augmented Matrices

A shorthand for writing systems of equations.
Requirements: Systems of Eq. Difficulty: 1

Elementary Row Ops

The three legal moves in matrix algebra.
Requirements: Intro to Matrices Difficulty: 2

Gaussian Elimination

The step-by-step algorithm to solve systems.
Requirements: Systems of Eq. Difficulty: 2

Row Echelon Form (REF)

The goal of Gaussian elimination.
Requirements: Gaussian Elim. Difficulty: 2

Reduced Row Echelon (RREF)

Simplifying systems to find unique solutions.
Requirements: REF Difficulty: 2

Chapter 5: Vector Spaces

Rank of a Matrix

Counting the "useful" information in a matrix.
Requirements: RREF Difficulty: 3

Null Space (Kernel)

Finding vectors that a matrix squashes to zero.
Requirements: Linear Transf. Difficulty: 3

Column Space (Image)

The set of all possible outputs of a matrix.
Requirements: Span Difficulty: 3

Row Space

The space spanned by the rows of a matrix.
Requirements: Column Space Difficulty: 3