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0 votes
1 answer
201 views

Splitting field of $x^3 +x +1$ over $\mathbb F_{11}$

This is a HW problem for an algebra course. Determine the splitting field of $f(x)=x^3+x+1$ over $\mathbb F_{11}$. I tried to use the answers from this question and this question to help me, but want ...
pyridoxal_trigeminus's user avatar
1 vote
1 answer
50 views

If $F$ is a field $a\in F$, if $(x-a)^n$ for $n\geq 2$ divides $r(x)$ then $r(a)=r^{\prime}(a)=0$

Statment: If $F$ is a field $a\in F$, if $(x-a)^n$ for $n\geq 2$ divides $r(x)$ then $r(a)=r^{\prime}(a)=0$. Proof: Induction over $n$ Case $n=2$ Let $F$ be a field and $a\in F$ since $(x-a)^2 |r(x)$...
Alan Jr's user avatar
  • 165
1 vote
2 answers
140 views

The irreducibility of $X^3-X^2+1$ over $\mathbb{F}_9[X]$

Let $K$ be the field with $9$ elements. I am asked to study the irreducibility of the polynomial $f:=X^3-X^2+1$ over $K[X]$. I proceeded as follows. $\mathbb{Z}[i]/3\mathbb{Z}[i]$ is a field with $9$ ...
Alexdanut's user avatar
  • 2,827
3 votes
1 answer
79 views

Solution Verification: Factoring $\left|\begin{smallmatrix}x&y&z\\x^p&y^p&z^p\\x^{p^2}&y^{p^2}&z^{p^2}\end{smallmatrix}\right|$ over $\mathbb{Z}_p.$

Problem: Factor $\begin{vmatrix} x & y & z \\ x^p & y^p & z^p \\ x^{p^2} & y^{p^2} & z^{p^2} \end{vmatrix}$ over $\mathbb{Z}_p$ as a product of polynomials of the form $ax+by+...
Display name's user avatar
  • 5,230
0 votes
0 answers
52 views

Prove that each element of polynomial ring with irreducible characteristic has exactly one minimum polynomial.

I have the following problem: Suppose $p$ is a prime and $f$ an irreducible polynomial in the ring $\Bbb{Z}/p\Bbb{Z}[X]$. Define a field $\mathbb{K}=\Bbb{Z}/p\Bbb{Z}[X]/(f)$ with the characteristic ...
Sei Sakata's user avatar
0 votes
0 answers
40 views

multiplication of polynomials in $\mathbb{F}_2[x]$

Let $p(x) = 1 + x + x^2$ and $q(x) = 1 + x + x^3$. Then is the multiplication $p(x)q(x)$ obtained like this: $$p(x)q(x)= (1 + x + x^2)(1 + x + x^3) = 1 +x +x^3 + x + x^2 + x^4 + x^2 + x^3 + x^5 $$ $$=...
mandella's user avatar
  • 1,862
1 vote
0 answers
285 views

Number of Roots of a Quadratic Modulo Prime Powers

I am an undergraduate and have been working on some research that I plan to publish. Part of the proof for one of my theorems relies on proving that an equation of the form $ax^2 + bx + c \equiv 0 \...
Will Craig's user avatar
2 votes
1 answer
2k views

Proving a polynomial is irreducible over a finite field

Question: $\mathbb{F}_5=\{0,1,2,3,4,5\}$ be the field with $5$ elements, let $\mathbb{F}_5[X]$ be the polynomial ring over $\mathbb{F}_5$. Let $m(X) = X^2+X+1$. Prove that $m(X)$ is irreducible over $\...
aoshdosi's user avatar
4 votes
1 answer
53 views

Find the degree of the polynomials in the following groups

Let $f(x) = x^4 + 6x^3 + 15x^2 + 10x + 1$ and $g(x) = 2x^2 + 15x + 1$. Consider $f$ and $g$ as polynomials with coefficients in (a) $\mathbb Q$, (b) $\mathbb F_2$, (c) $\mathbb F_3$, and (d) $\mathbb ...
mike russel's user avatar