What are the elements of Alt_4 ?

  • Thread starter Thread starter quasar987
  • Start date Start date
  • Tags Tags
    Elements
quasar987
Science Advisor
Homework Helper
Gold Member
Messages
4,796
Reaction score
32

Homework Statement


This is not HW per say, I'm just wondering what the elements of Alt_4 are (the subgroup of S4 consisting of all even permutations). I know Alt_4 is of order 4!/2=12, and I have so far that

Id, (1 2 3), (1 2 4), (1 3 4), (2 3 4), (1 2)(3 4), (1 3)(2 4), (1 4)(2 3)

are in Alt_4 but what are the other four elements??
 
Physics news on Phys.org
How about (1,3,2) for example?
 
Right, I forgot those.

(1,3,2), (1 4 2), (1 4 3) and (2 4 3)

the inverses of the four elements I listed.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
Back
Top