MathDB
Miklós Schweitzer 1961- Problem 3

Source:

November 22, 2015
college contests

Problem Statement

3. Let f(x)=xn+a1x(n1)++anf(x)= x^n +a_1 x^(n-1)+ \dots + a_n (n1n\geq 1) be an irreducible polynomial over the field KK. Show that every non-zero matrix commuting with the matrix [010000010000001anan1an2a2a1</br>] \begin{bmatrix} 0 & 1 & 0 & \dots & 0 & 0 \\ 0 & 0 & 1 & \dots & 0 & 0 \\ \dots & \dots & \dots & \dots & \dots & \dots \\ 0 & 0 & 0 & \dots & 0 & 1 \\ -a_n & -a_{n-1} & -a_{n-2} & \dots & -a_2 & -a_1 </br>\end{bmatrix} is invertible. (A. 4)