## Precalculus (6th Edition) Blitzer

The inverse is, $A=\left[ \begin{matrix} 0 & -1 & 0 & 1 \\ -1 & -5 & 0 & 3 \\ -2 & -4 & 1 & -2 \\ -1 & -4 & 0 & 1 \\ \end{matrix} \right]$.
Consider the given matrix, $A=\left[ \begin{matrix} 7 & -3 & 0 & 2 \\ -2 & 1 & 0 & -1 \\ 4 & 0 & 1 & -2 \\ -1 & 1 & 0 & -1 \\ \end{matrix} \right]$ We have to find the inverse of matrix $A$ by using a calculator. We will follow the steps given below: (1) We select the matrix $A$ from the matrix edit menu and then enter or accept the dimensions. (2) Use ${{2}^{nd}}$ and press the matrix button. (3) Select the matrix $A$ and use the function ${{X}^{-1}}$ for the inverse of matrix $A$ and press enter. (4) We find the ${{A}^{-1}}$ Therefore, the inverse of the matrix $A$ is $\left[ \begin{matrix} 0 & -1 & 0 & 1 \\ -1 & -5 & 0 & 3 \\ -2 & -4 & 1 & -2 \\ -1 & -4 & 0 & 1 \\ \end{matrix} \right]$. Now, checking the result, show that $A{{A}^{-1}}=I$. We multiply matrix $A$ with ${{A}^{-1}}$ and obtain the identity matrix. Hence, the inverse of the given matrix is correct.