Results 1 to 2 of 2

Math Help - Finding inverses

  1. #1
    Newbie
    Joined
    May 2011
    From
    Florida
    Posts
    16

    Finding inverses

    Just wondering if there was a method to find inverses besides just guess and check. I need to find for Z/365Z the inverses of [53], [73], [93], and [113]
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member
    Joined
    Feb 2008
    Posts
    410

    Re: Finding inverses

    Quote Originally Posted by scruz10 View Post
    Just wondering if there was a method to find inverses besides just guess and check. I need to find for Z/365Z the inverses of [53], [73], [93], and [113]
    Under addition we the have -[53]=[-53], and so on. Multiplication is a bit trickier. Use the Euclidean algorithm to find a,b such that 53a+365b=1. Then [53]^{-1}=[a]. However keep in mind that [73] is NOT an element of the multiplicative group Z/365Z (because (73,365)=73).
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Advanced Calculus -- Finding the local inverses of f
    Posted in the Differential Geometry Forum
    Replies: 4
    Last Post: November 14th 2011, 08:45 AM
  2. Algebra: Finding Inverses
    Posted in the Algebra Forum
    Replies: 2
    Last Post: November 10th 2010, 04:44 AM
  3. Finding Inverses and Verify
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: November 4th 2009, 02:34 PM
  4. Logs- finding inverses
    Posted in the Algebra Forum
    Replies: 3
    Last Post: July 19th 2009, 05:46 AM
  5. Finding Inverses Using Composition of Functions
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: December 22nd 2008, 07:10 PM

Search Tags


/mathhelpforum @mathhelpforum