Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Modulo arthmetic solve for x^N .

  1. Nov 16, 2009 #1
    Modulo arthmetic solve for x^N.....

    Hay all, I am stuck on a problem, and its driving me crazy. I have a problem, xN = a mod b. Where I have to solve for x. My first thought was use to Fermat's little theorem(if I have the name correct), however my b is not a prime, (neither is 'N' or 'a' for that fact). I can give the exact problem with numbers if needed, but thought it would be slightly easier with variables instead. Any tips on how I could start to solve this would be great. Any questions please ask.
     
  2. jcsd
  3. Nov 16, 2009 #2
    Re: Modulo arthmetic solve for x^N.....

    I believe there is no generic solution to this problem.
     
  4. Nov 16, 2009 #3
    Re: Modulo arthmetic solve for x^N.....

    Giving the actual numbers would probably be best for this one.
     
  5. Nov 16, 2009 #4
    Re: Modulo arthmetic solve for x^N.....

    Google nth power residue for lots of results (and references to specific number theory texts) regarding your question.

    Petek
     
  6. Nov 16, 2009 #5

    Hurkyl

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Re: Modulo arthmetic solve for x^N.....

    Chinese remainder theorem.
     
  7. Nov 17, 2009 #6

    CRGreathouse

    User Avatar
    Science Advisor
    Homework Helper

    Re: Modulo arthmetic solve for x^N.....

    Yes. Factor b, use Fermat, then CRT the results together.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Modulo arthmetic solve for x^N .
  1. Integers Modulo n (Replies: 4)

  2. The Integers Modulo n (Replies: 9)

  3. Solving x^{n}+a=mod(b) (Replies: 8)

Loading...