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!

HELP PLEASE -Isomorphisms Really Hard

  1. Feb 11, 2009 #1
    Construct an isomorphism

    A4 (AND) D4 ---> (Z/2,+)X(Z/2,+)

    where D4's the symmetries of the square

    so I found D4(And)A4={(13)(24),Id,(12)(34),(14)(23)}
  2. jcsd
  3. Feb 12, 2009 #2


    User Avatar
    Science Advisor

    Then you are trying too hard! Map the identity to the identity of (Z/2,+)x(Z/2,+), (0,0). Then map (13)(24), (12)(34), (14)(23) to (0,1), (1,0), (1,1) any way you like. You will get an isomorphism.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook