1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Linear Algebra help - !

  1. Nov 18, 2006 #1
    Linear Algebra help -urgent!

    I'm doing a bit of self learning on Linear Algebra but I'm kinda confused with the information given on odd and even permutations?

    How do you determine whether a permutation is odd or even?

    For example, the book has given some examples such as:

    (1 2 3 4) is odd, (1 3)(2 4) is even? :confused:

    Can someone help please? Thank you!
  2. jcsd
  3. Nov 18, 2006 #2


    User Avatar
    Homework Helper

    Try to count the 'steps' you need to do a permutation and see if the number is odd or even.
  4. Nov 18, 2006 #3
    A permutation is even if it's the product of an even number of 2-cycles. That's why (1 3)(2 4) is even. A permutation is odd if it isn't even. (1 2 3 4 ) written as two cycles would be (1 4)(1 3)(1 2) which is odd.
  5. Nov 18, 2006 #4
    Thanks guys! I get it now :biggrin:
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook