3. For the matrix B, find p(B) and note that $p(B) \le p(A)$ since $B = A$, where A is defined in Prob. 1 and B is given below.

$$

B = \begin{bmatrix}

1 & 3 & 1 \\

1 & 1 & 3 \\

3 & 1 & 1

\end{bmatrix}

$$

This illustrates (4) of Theorem 11.1.1.