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#1 2009-03-25 05:22:00

LuisRodg
Real Member
Registered: 2007-10-23
Posts: 322

Help. (groups)

The solution to this problem is in the Solutions Manual. Here it is:

grp.jpg

We havent covered fields in class, nor Zorn's lemma. I wonder why they put this kind of solution when it uses stuff we havent covered. Is there a way to do this problem using only groups, like, not using any of the stuff that the solution says "the reader is not yet prepared for" ?

Last edited by LuisRodg (2009-03-25 05:22:24)

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#2 2009-03-25 06:22:34

Ricky
Moderator
Registered: 2005-12-04
Posts: 3,791

Re: Help. (groups)

If you ignore the infinite case, there is no need for Zorn's Lemma.  So we are assuming G is finite.  You should be ok with the fact that G is abelian and x = -x.  Do you know the fundamental theorem for finite(ly generated) abelian groups?  That every finite abelian group is isomorphic to a finite number of copies of the integers modulo p (i.e. cyclic groups).  Assuming you know this, consider the map that just moves around these generators.  It is an automorphism and you can choose it to be non-trivial as long as G has more than one copy of the integers modulo p.  We conclude from this that G is in fact the integers modulo p.  But the requirement of x = -x now forces p = 2.


"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."

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#3 2009-03-25 06:59:02

Daniel123
Member
Registered: 2007-05-23
Posts: 663

Re: Help. (groups)

"but the poor reader is not prepared for this"

what a strange book.

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#4 2009-03-25 09:50:02

daonly1pinkcutie
Member
Registered: 2009-03-25
Posts: 3

Re: Help. (groups)

hey could you help me with completing squares? its something that we are doing in algebra 1 right now


Br!++n3y Myl3$

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#5 2009-03-25 09:52:30

LuisRodg
Real Member
Registered: 2007-10-23
Posts: 322

Re: Help. (groups)

Please make a new post and we will try to help you.

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#6 2009-03-25 09:59:47

daonly1pinkcutie
Member
Registered: 2009-03-25
Posts: 3

Re: Help. (groups)

hey wats up my name is brittney could you help me with my math homework?::D


Br!++n3y Myl3$

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