Determinants and inverses of large matrices

5 videos
2 skills
Learn how to find the determinants and the inverses of matrices with dimensions 3x3 or larger.

Determinant of a 3x3 matrix: standard method (1 of 2)

VIDEO 3:57 minutes
Sal shows the standard method for finding the determinant of a 3x3 matrix.

Determinant of a 3x3 matrix: shortcut method (2 of 2)

VIDEO 2:39 minutes
Sal shows a "shortcut" method for finding the determinant of a 3x3 matrix.

Determinant of a 3x3 matrix

PRACTICE PROBLEMS
Find the determinant of a given 3x3 matrix.

Inverting a 3x3 matrix using Gaussian elimination

VIDEO 13:36 minutes
Sal explains how we can find the inverse of a 3x3 matrix using Gaussian elimination.

Inverting a 3x3 matrix using determinants Part 1: Matrix of minors and cofactor matrix

VIDEO 8:47 minutes
Sal shows how to find the inverse of a 3x3 matrix using its determinant. In Part 1 we learn how to find the matrix of minors of a 3x3 matrix and its cofactor matrix.

Inverting a 3x3 matrix using determinants Part 2: Adjugate matrix

VIDEO 6:23 minutes
Sal shows how to find the inverse of a 3x3 matrix using its determinant. In Part 2 we complete the process by finding the determinant of the matrix and its adjugate matrix.

Inverse of a 3x3 matrix

PRACTICE PROBLEMS
Find the inverse of a given 3x3 matrix.