[行列解析5.6.P35]

|\tilde{z}| \le \max\left\{\begin{aligned}
& |a_0| r^{n-1}, \\
& |a_1| r^{n-2} + r^{-1}, \\
& |a_2| r^{n-3} + r^{-1}, \\
& \dots,\\ 
& |a_{n-2}| r + r^{-1}, \\
& |a_{n-1}| + r^{-1}
\end{aligned}
\right\} \\
\le \frac{1}{r} + \max_{0 \le k \le n-1} \left\{|a_k| r^{n-k-1}\right \}, \\\quad r > 0