# Prove that any cyclic group of finite order n is isomorphic to Zn under addition.

• Apr 12th 2010, 07:38 AM
rainyice
Prove that any cyclic group of finite order n is isomorphic to Zn under addition.
Prove that any cyclic group of finite order n is isomorphic to Zn under addition.

Should I draw two tables to indicate that? Like ... the first one is cyclic group table G and the second one is the Zn table H, then I linked it G -> f -> H where f is the transformation.
• Apr 12th 2010, 08:24 AM
tonio
Quote:

Originally Posted by rainyice
Prove that any cyclic group of finite order n is isomorphic to Zn under addition.

Should I draw two tables to indicate that? Like ... the first one is cyclic group table G and the second one is the Zn table H, then I linked it G -> f -> H where f is the transformation.

Too many questions , too little work shown: what've you done to solve these questions? Where are you stuck?

Tonio
• Apr 12th 2010, 09:11 AM
Bruno J.
Quote:

Originally Posted by rainyice
Prove that any cyclic group of finite order n is isomorphic to Zn under addition.

Should I draw two tables to indicate that? Like ... the first one is cyclic group table G and the second one is the Zn table H, then I linked it G -> f -> H where f is the transformation.

Hint : map a generator to a generator, and extend the map to a homomorphism in the only possible way; then show that it's an isomorphism.
• Apr 13th 2010, 07:06 PM
MissMousey
Working on the same problem
Quote:

Originally Posted by rainyice
Prove that any cyclic group of finite order n is isomorphic to Zn under addition.

Should I draw two tables to indicate that? Like ... the first one is cyclic group table G and the second one is the Zn table H, then I linked it G -> f -> H where f is the transformation.

I don't think drawing tables qualifies as a proof (I'm working on the same problem). Also, you weren't told what operation "G" was under, so you wouldn't be able to make a table for cyclic group G.

I believe we have to show that some generator <x> of G maps into some generator <a> of Z. To show isomorphism, we have to satisfy two conditions. To show
φ (some function) is a one-to-one correspondence from G to Z, we need to show that every element in G maps into every element in Z. For this one, I'm assuming since both groups are of the same order (we stated that cyclic group G is of order n and it is given that Z is of order n), there is automatically a one-to-one correspondence between the two groups (I'm not sure though).

I'm still working on showing the second condition of isomorphism. (Worried)

• Apr 13th 2010, 07:09 PM
Drexel28
Quote:

Originally Posted by MissMousey
I don't think drawing tables qualifies as a proof (I'm working on the same problem). Also, you weren't told what operation "G" was under, so you wouldn't be able to make a table for cyclic group G.

I believe we have to show that some generator <x> of G maps into some generator <a> of Z. To show isomorphism, we have to satisfy two conditions. To show
φ (some function) is a one-to-one correspondence from G to Z, we need to show that every element in G maps into every element in Z. For this one, I'm assuming since both groups are of the same order (we stated that cyclic group G is of order n and it is given that Z is of order n), there is automatically a one-to-one correspondence between the two groups (I'm not sure though).

I'm still working on showing the second condition of isomorphism. (Worried)

Some people call me the gangster of love.