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1 vote
0 answers
42 views

If $f(x)=ax^{2p}+bx^p+c\in\mathbb{F}_p[x]$, prove that $f'(x)=0$

If $R$ is a commutative ring, then the set of all polynomials with coefficients in $R$ is denoted by $R[x]$. $\mathbb{I}_p[m]$ is the integers mod $m$. When $p$ is a prime, we will usually denote the ...
Junk Warrior's user avatar
-1 votes
1 answer
1k views

What is the inverse of an element of polynomial ring over finite field?

Let's consider the polynomial ring $\mathbb{F}_q[x]$. How to find the inverse of an element of this ring. For example, If I'm working over $\mathbb{Z}_7[x]$, what is the inverse of $x^2+x+1$. This is ...
student's user avatar
  • 175
1 vote
1 answer
55 views

Let p be prime and Fpm denote the field with pm elements. Let k,n be in N.

I am just trying to solve the first part I think I understand how to attempt this problem using a specific p, k, and n, my steps are as follows: We know that the field $\mathbb F_{p^m}$ = the roots ...
Christopher's user avatar
2 votes
0 answers
245 views

Applications of the Hermite's criterion?

I found this statement on permutation polynomials and I was wondering in which domain we can find applications and what is its aim. Here is the criterion : «If $q=p^n$ with $p$ a prime number then $f\...
Maman's user avatar
  • 3,330
1 vote
2 answers
327 views

Irreducible polynomials in GF(p) [duplicate]

Given is the polynomial $\varphi(X)=X^4+1$. Now there are two tasks: (1) Show, that $ \varphi(X)$ is reducible in $\mathbb F_p [X]$, where $p$ is prime number with $p \equiv1$ (mod 4). (2) Show, ...
Myrkuls JayKay's user avatar
4 votes
1 answer
241 views

Cubic root of a polynomial to modulo of another polynomial

Is there any algorithm to solve problems like the problem below, any ideas? Find polynomial $f$ such that: $f^3 \equiv x^4 + x^2 \ (mod\ x^{10} + x^3 + 1)$ All numeric coefficients are from $\...
Blendamed's user avatar
  • 125
0 votes
1 answer
239 views

monic irreducible polynomials

I need help with : Let $\Bbb F_3=\Bbb Z_3$ be the field with 3 elements.Show that there are infinitely many monic irreducible polynomials in $\Bbb F_3[x]$ such that $P(0)=-1$. Now,I saw this proof ...
ChikChak's user avatar
  • 2,002
6 votes
2 answers
100 views

Roots of $x^p + x + [\alpha]_p \in \mathbb{F}_p[x]$

Let $$g(x) = x^p + x + [\alpha]_p \in \mathbb{F}_p[x],$$ where $p$ is prime. For which $\alpha, p \in \mathbb{Z}$ does $g(x)$ have at least one root? And for which $\alpha, p \in \mathbb{Z}$ does $g(...
user avatar
3 votes
2 answers
2k views

$x^p-x \equiv x(x-1)(x-2)\cdots (x-(p-1))\,\pmod{\!p}$

I got a question to show that : If $p$ is prime number, then $$x^p - x \equiv x(x-1)(x-2)(x-3)\cdots (x -(p-1))\,\,\text{(mod }\,p\text{)}$$ Now I got 2 steps to show that the two polynomials ...
morgan's user avatar
  • 33
3 votes
1 answer
680 views

Factoring polynomials of the form $1+x+\cdots +x^{p-1}$ in finite field

Suppose $p$ and $q$ primes and $p$ is odd. Then, are there nice and clever ways to factorize polynomials of the form $$f(x)=1+x+\cdots +x^{p-1}$$ in the ring $\mathbb{F}_q[x]$ ? What about the case ...
pritam's user avatar
  • 10.2k