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: Subsets and Groups

  1. May 22, 2012 #1
    Hey guys, I'm having an issue with a question, namely

    Let x be a subset of S4. Is x a group?

    x = {e, (123), (132), (12)(34)}

    I don't really understand how I can test the 4 axioms of a group and how x being a subset of S4 would help?
  2. jcsd
  3. May 22, 2012 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Education Advisor

    You have only four elements. Why not just write out the entire multiplication table and see if you have a group on your hands?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook