• #### The Identity Matrix - Concept

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to determine the identity matrix of order n.
• #### Area With Determinants - Concept

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to compute the area of a parallelogram using a determinant.
• #### Square Matrices - Problem 3

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to show that two matrices are inverses (in the sense of matrix multiplication).
• #### Square Matrices - Concept

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to determine whether two matrices can be multiplied, and if so, what the dimensions of the product will be.
• #### Introduction to the 3D Coordinate System - Problem 2

##### Math›Precalculus›Vectors and Parametric Equations
How to find the equation of a sphere with radius r when it is centered at the origin.
• #### The Inverse of a Square Matrix - Concept

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to determine whether two matrices are inverses.
• #### Area With Determinants - Problem 3

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to compute the area of an irregular quadrilateral using determinants.
• #### The Cross Product of Vectors - Concept

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to compute the cross product of two 3D vectors.
• #### Square Matrices - Problem 1

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to demonstrate that matrix multiplication is not commutative.
• #### 2x2 Determinants - Concept

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to compute the determinant of a 2x2 square matrix.
• #### Simplifying Determinants - Concept

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to simplify determinants using three row (or column) operations.
• #### Area With Determinants - Problem 1

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to compute the area of a triangle using a determinant.
• #### Square Matrices - Problem 2

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to interpret 2x2 matrices as transformations.
• #### Area With Determinants - Problem 2

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to use the triangle area formula to test three points for collinearity.
• #### The Inverse of a Square Matrix - Problem 2

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to determine that a matrix has no inverse using row operations.
• #### The Inverse of a Square Matrix - Problem 1

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to find the inverse of a square matrix of order 2 using row operations.
• #### The Inverse of a Square Matrix - Problem 3

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to find the inverse of a square matrix of order 3 using row operations.
• #### 3x3 Determinants - Concept

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to compute the determinant of a 3x3 square matrix using minors by expanding along the top row.
• #### 3x3 Determinants - Problem 2

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to determine the effect of interchanging two rows on the value of a determinant.
• #### Simplifying Determinants - Problem 2

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to compute a 3x3 determinant using row operations to simplify it first.