1. Not finding help here? Sign up for a free 30min 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!

Proving H is normal

  1. Oct 31, 2008 #1
    1. The problem statement, all variables and given/known data

    If G is a finite group that has exactly one subgroup H of a given order, then H is normal.

    2. Relevant equations

    N/A

    3. The attempt at a solution

    I cannot figure out what makes a subgroup H special if it is the only one of a given order...
     
  2. jcsd
  3. Oct 31, 2008 #2
    Pick a g in G. What is the order of g-1Hg?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?