Ask Me Help Desk

Ask Me Help Desk (https://www.askmehelpdesk.com/forum.php)
-   Math & Sciences (https://www.askmehelpdesk.com/forumdisplay.php?f=402)
-   -   Are these polynomials irreducible over integers ? (https://www.askmehelpdesk.com/showthread.php?t=613340)

  • Nov 19, 2011, 02:27 AM
    princeps
    Are these polynomials irreducible over integers ?
    Is it true that polynomials of the form :

    [itex] f_n= x^n x^{n-1} \cdots x^{k 1} ax^k ax^{k-1} \cdots a [/itex]

    where [itex]\gcd(n 1,k 1)=1[/itex] , [itex] a\in \mathbb{Z^{ }}[/itex] , [itex]a[/itex] is odd number , [itex]a>1[/itex], and [itex]a_1\neq 1[/itex]

    are irreducible over the ring of integers [itex]\mathbb{Z}[/itex]?

    Eisenstein's criterion , Cohn's criterion , and Perron's criterion cannot be applied to the polynomials of this form.

    Example :

    The polynomial [itex]x^4 x^3 x^2 3x 3[/itex] is irreducible over the integers but none of the criteria above can be applied on this polynomial.
  • Nov 19, 2011, 07:42 AM
    princeps
    Relations between coefficient and exponent of Proth prime ?
    Definition: Proth number is a number of the form :

    [IMG]<img src="/cgi-bin/mathtex.cgi?k\cdot 2^n 1[/IMG]

    where k is an odd positive integer and n is a positive integer such that : [IMG]<img src="/cgi-bin/mathtex.cgi?2^n>k[/IMG]

    My question : If Proth number is prime number are there some other known relations in addition to [IMG]<img src="/cgi-bin/mathtex.cgi?2^n>k[/IMG] , between exponent n and coefficient k ?
  • Nov 19, 2011, 07:50 AM
    princeps
    Relations between coefficient and exponent of Proth prime
    Definition: Proth number is a number of the form :



    where is an odd positive integer and is a positive integer such that :

    My question : If Proth number is prime number are there some other known relations in addition to , between exponent and coefficient ?

  • All times are GMT -7. The time now is 12:27 PM.