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Algebra proof question help

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Very confused on this proof, not sure how to construct the proof of these 3 questions :/
Reply 1
Reply 2
Original post by maths10101
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Very confused on this proof, not sure how to construct the proof of these 3 questions :/


Let's say that if we have gGg \in G, then gn=eg^n = e where n is the order of g. This also means that gkeg^k \neq e where 1k<n1 \leq k < n.

Now we have: e=f(e)=f(gn)=f(g)ne' = f(e) = f(g^n) = f(g)^n, now can you use the fact that ff is a bijection, along with gkeg^k \neq e to get your result?
Reply 3
where have all the purists gone?
where is
DFranklin
ghostwalker
Davros
Smaug123

to name a few
Reply 4
Original post by TeeEm
where have all the purists gone?
where is
DFranklin
ghostwalker
Davros
Smaug123

to name a few


Smaug is still around, I think, but busy with Part III. Not sure where the others have disappeared to.
Reply 5
Original post by Zacken
Smaug is still around, I think, but busy with Part III. Not sure where the others have disappeared to.


I remembered another one fireGarden or something... gone too
Reply 6
Original post by Zacken
Let's say that if we have gGg \in G, then gn=eg^n = e where n is the order of g. This also means that gkeg^k \neq e where 1k<n1 \leq k < n.

Now we have: e=f(e)=f(gn)=f(g)ne' = f(e) = f(g^n) = f(g)^n, now can you use the fact that ff is a bijection, along with gkeg^k \neq e to get your result?


Oh okay, I'm slowly starting to understand it..is this for part a right? And would that be the full proof or would you think there's more?
Reply 7
Original post by maths10101
Oh okay, I'm slowly starting to understand it..is this for part a right? And would that be the full proof or would you think there's more?


Yes, for part (a). For part(b) find an element that does not obey the thing proved in part(a) to show that they aren't isomorphic.

If you fill in the blanks I left, that's the full proof, it's not very long. Just needs some heavy ideas.

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