## Determine whether the Given 3 by 3 Matrices are Nonsingular

## Problem 671

Determine whether the following matrices are nonsingular or not.

**(a)** $A=\begin{bmatrix}

1 & 0 & 1 \\

2 &1 &2 \\

1 & 0 & -1

\end{bmatrix}$.

**(b)** $B=\begin{bmatrix}

2 & 1 & 2 \\

1 &0 &1 \\

4 & 1 & 4

\end{bmatrix}$.