Instructional Video
Khan Academy

Khan Academy: Inverting Matrices: Singular Matrices

9th - 10th Standards
Video explains why a matrix is singular if its determinant is 0. Relates why the inverse does not exist to solving systems of linear equations and vector combinations.
Instructional Video
Khan Academy

Khan Academy: More Determinant Depth: Determinant When Row Is Added

9th - 10th Standards
A video lesson explaining the determinant rule for the very special case when three matrices are identical except for one row, and that row of the third matrix is the sum of those rows in the other two matrices.
Instructional Video
Khan Academy

Khan Academy: Transpose of a Matrix: Determinant of Transpose

9th - 10th Standards
This videos offers a proof by induction that transposing a matrix does not change its determinant.
Instructional Video
Khan Academy

Khan Academy: Simplifying Conditions for Invertibility

9th - 10th Standards
A video lesson explaining that a transformation matrix is invertible if and only if it is a square identity matrix in reduced row echelon form.
Instructional Video
Khan Academy

Khan Academy: Finding Inverses of Matrices: Formula for 2 X2 Inverse

9th - 10th Standards
Figuring out the formula for a 2x2 matrix. Defining the determinant.
Instructional Video
Khan Academy

Khan Academy: Finding Inverses of Matrices: Rule of Sarrus of Determinants

9th - 10th Standards
A alternative "short cut" for calculating 3x3 determinants (Rule of Sarrus)
Instructional Video
Khan Academy

Khan Academy: Finding the Determinant of a 3 X3 Matrix Method 2

9th - 10th Standards
This video shows how to find the determinant of a thre by three matrix.
Instructional Video
Khan Academy

Khan Academy: Finding the Determinant of a 3 X3 Matrix Method 1

9th - 10th Standards
A video showing how to find the determinant of a 3 x 3 matrix.
Instructional Video
Instructional Video
Khan Academy

Khan Academy: Inverting Matrices: Inverse of a 2 X2 Matrix

9th - 10th Standards
Example of calculating the inverse of a 2x2 matrix.
Instructional Video
Other

Identity Matrix and Inverses

9th - 10th Standards
Explains what is meant by an identity matrix and why it is important. This is followed by a discussion of inverses. Examples and explanations are very clear. [13:45]
Instructional Video
Khan Academy

Khan Academy: Inverting 3 X3 Part 2: Determinant and Adjugate of a Matrix

9th - 10th Standards
This is part two of video about 3x3 matrix inversion.
Instructional Video
Khan Academy

Khan Academy: Inverting Matrices: Finding the Determinant of a 2 X2 Matrix

9th - 10th Standards
Hint for finding the determinant of a 2x2 matrix,
Instructional Video
Khan Academy

Khan Academy: Properties of Matrix Multiplication: Zero Matrix

9th - 10th Standards
Explains what the zero matrix is and how it is used in matrix multiplication. [4:41]
Instructional Video
Khan Academy

Khan Academy: Matrix Multiplication: Identity and Zero Matrix Equation

9th - 10th Standards
Models a problem where one must determine whether unknown matrices are zero or identity to make an equation true. [3:58]
Instructional Video
Khan Academy

Khan Academy: Properties of Matrix Multiplication: Intro to Identity Matrix

9th - 10th Standards
Just as any number remains the same when multiplied by 1, any matrix remains the same when multiplied by the identity matrix. [7:59]
Instructional Video
Khan Academy

Khan Academy: 3x3 Determinant

9th Standards
Determinants: Finding the determinant of a 3x3 matrix.
Instructional Video
Sophia Learning

Sophia: Finding the Determinant of a 2 X 2 Matrix: Lesson 5

9th - 10th Standards
This lesson demonstrates how to find the determinant of a 2x2 matrix. It is 5 of 6 in the series titled "Finding the Determinant of a 2 x 2 Matrix."
Instructional Video
Sophia Learning

Sophia: Finding the Determinant of an Inverse Matrix: Lesson 2

9th - 10th Standards
In this lesson students will learn how to find the determinant of an inverse matrix. It is 2 of 5 in the series titled "Finding the Determinant of an Inverse Matrix."
Instructional Video
Sophia Learning

Sophia: Finding the Determinant of an Inverse Matrix: Lesson 4

9th - 10th Standards
In this lesson students will learn how to find the determinant of an inverse matrix. It is 4 of 5 in the series titled "Finding the Determinant of an Inverse Matrix."
Instructional Video
Sophia Learning

Sophia: Using Determinants to Classify 2x2 Matrices

9th - 10th Standards
This lesson demonstrates how the determinant of a 2x2 matrix can be used to tell whether or not the matrix represents a dependent linear system, an inconsistent linear system, or neither.
Instructional Video
Sophia Learning

Sophia: Verifying That Matrices Are Inverses: Lesson 3

9th - 10th Standards
This lesson demonstrates how to determine whether or not matrices are inverse. It is 3 of 7 in the series titled "Verifying that Matrices are Inverses."
Instructional Video
Sophia Learning

Sophia: Verifying That Matrices Are Inverses: Lesson 7

9th - 10th Standards
This lesson demonstrates how to determine whether or not matrices are inverse. It is 7 of 7 in the series titled "Verifying that Matrices are Inverses."
Instructional Video
Sophia Learning

Sophia: Verifying That Matrices Are Inverses: Lesson 1

9th - 10th Standards
This lesson demonstrates how to determine whether or not matrices are inverse. It is 1 of 7 in the series titled "Verifying that Matrices are Inverses."