Order of Homomorphisms from Z to Z/2Z - Help Needed

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SUMMARY

There are exactly two group homomorphisms from the group of integers Z to the group Z/2Z. The first is the trivial homomorphism that maps every integer to 0 in Z/2Z. The second homomorphism maps even integers to 0 and odd integers to 1, defined by the function f(n) = n (mod 2). This mapping is established by the fact that Z is generated by 1, which can either map to 0 or 1 in Z/2Z.

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  • Understanding of group theory concepts, specifically homomorphisms.
  • Familiarity with modular arithmetic, particularly Z/2Z.
  • Knowledge of integer properties, such as even and odd classification.
  • Basic comprehension of generators in group theory.
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Students and enthusiasts of abstract algebra, particularly those studying group theory and homomorphisms, will benefit from this discussion.

jakelyon
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I have seen that there exists two group homomorphisms from Z to Z/2Z. However, I cannot seem to understand this. I mean I know that there exists a trivial grp hom. which sends all of Z to 0 in Z/2Z. But I cannot think of anymore. Any help?
 
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Well, Z is generated by 1. There are two places 1 can map to, 0 or 1 (mod 2). If it doesn't map to 0, it must map to 1. Do you see what function that really is?
 
You mean that I map all even to 0 and all odd to 1?
 
Yes :)
If f(1)=1 (mod 2), then f(n)=n (mod 2), which is 0 if n is even and 1 if n is odd.
 

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