Finding the Inverse of a Matrix

Question

Suppose x ∈ R.

Find the inverse of the following matrix:

A = [ 1 1 1 ]

[ 0 1 1 ]

[ x 0 1 ]

Answer 1

There is more than one way to find an inverse. You’ll need to address which method is required else you may receive a solution far beyond your current place in the text/course.

[ A | I ] ~ [ I | A^(-1) ]

Just reducing RREF the above matrix A = to the identity will result in inverse.

or

A^(-1) = adj(A)/det(A)