To find the inverse of a 3×3 matrix A say, (Last video) you will need to be familiar with several new matrix methods first

  1. Finding the minor of each element of matrix A
  2. Finding the cofactor of matrix A

With these I show you how to find the inverse of a matrix A

where I use the example

A= \begin{pmatrix} 2 & 4 & -5 \\5 & -1 & 3 \\1 & -2 & 4 \end{pmatrix}

Prerequisite: Finding minors of elements in a 3×3 matrix

Finding the cofactor of a 3×3 matrix

Putting it all together – Finding the inverse of a 3×3 matrix

Example to try