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Miklós Schweitzer
1961 Miklós Schweitzer
3
Miklós Schweitzer 1961- Problem 3
Miklós Schweitzer 1961- Problem 3
Source:
November 22, 2015
college contests
Problem Statement
3. Let
f
(
x
)
=
x
n
+
a
1
x
(
n
−
1
)
+
⋯
+
a
n
f(x)= x^n +a_1 x^(n-1)+ \dots + a_n
f
(
x
)
=
x
n
+
a
1
x
(
n
−
1
)
+
⋯
+
a
n
(
n
≥
1
n\geq 1
n
≥
1
) be an irreducible polynomial over the field
K
K
K
. Show that every non-zero matrix commuting with the matrix
[
0
1
0
…
0
0
0
0
1
…
0
0
…
…
…
…
…
…
0
0
0
…
0
1
−
a
n
−
a
n
−
1
−
a
n
−
2
…
−
a
2
−
a
1
<
/
b
r
>
]
\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}
0
0
…
0
−
a
n
1
0
…
0
−
a
n
−
1
0
1
…
0
−
a
n
−
2
…
…
…
…
…
0
0
…
0
−
a
2
0
0
…
1
−
a
1
<
/
b
r
>
is invertible. (A. 4)
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