P. 245, line 8

Use:

$A_7=\left[\begin{array}{cccc}2& -7& 6& -7\\ 0& 1& 0& -7\\ 0& -7& 8& -7\\ 0& 0& 0& 8\end{array}\right]$

instead. This matrix has repeated eigenvalues, but a linearly independent set of 4 eigenvectors.

Return to errata.