Abstract Algebra: Find Generators & Relations for Z2+Z2+Z2

tyrannosaurus
Messages
31
Reaction score
0

Homework Statement


What is the minimum number of generators needed for Z2+Z2+Z2? Find a set of generators and relations for this group.


Homework Equations





The Attempt at a Solution


I think it is obvious that the minimum amount of generators that you need is three, with Z2+Z2+Z2 = {a,b,c|a^2=b^2=c^2} but I don't know what I have to put down for the relations in the group and I am not sure how to explain that the minimum is 3 generators. Any help would be great!
 
Physics news on Phys.org
It's not 'obvious' that the minimal number of generators is three until you explain why you think it is. And I have no idea what Z2+Z2+Z2 = {a,b,c|a^2=b^2=c^2} is supposed to mean. Can you explain?
 
To show that you can't have two generators: what do you know about the order of elements in the group?

In terms of the relations, you definitely need more than just a^2=b^2=c^2=e since the group with that presentation is infinite. What about relations to make the group abelian?
 
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