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thus  <math> a^{n}=1</math> by the def of order
 
thus  <math> a^{n}=1</math> by the def of order
  
then <math>\phi_{a}^{n}(x)=a^{n}xa^{-1}=1x1=x</math> making x the identity
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then <math>\phi_{a}^{n}(x)=a^{n}xa^{-n}=1x1=x</math> making x the identity
  
 
since <math>\phi_{a}^{n}(x)=</math>identity then <math>|\phi_{a}(x)|=min(n, c) </math> were c is a division of n since any multiple of c, including n, will also give the identity
 
since <math>\phi_{a}^{n}(x)=</math>identity then <math>|\phi_{a}(x)|=min(n, c) </math> were c is a division of n since any multiple of c, including n, will also give the identity
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-zach
 
-zach
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Yeah, I just figured that out and was posting about it when you put that up. Thanks.

Latest revision as of 01:35, 25 September 2008

Any body have any ideas???? I'm lost.


I don't know either. I looked in the back of the book, but I don't see how what they're saying has anything to do with the problem. The back of the book is talking about how $ \phi_{a^{n}}=1 $, but I thought that we basically needed to show that $ \phi_{a}^{n}=1 $. All I can show is that $ \phi_{a}^{n}(x)=ax^{n}a^{-1} $, and that $ \phi_{a}^{n}(x)=x $ if G is abelian.

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What the book is saying:

let $ |a|=n $

thus $ a^{n}=1 $ by the def of order

then $ \phi_{a}^{n}(x)=a^{n}xa^{-n}=1x1=x $ making x the identity

since $ \phi_{a}^{n}(x)= $identity then $ |\phi_{a}(x)|=min(n, c) $ were c is a division of n since any multiple of c, including n, will also give the identity

hope this helps

-zach


Yeah, I just figured that out and was posting about it when you put that up. Thanks.

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Basic linear algebra uncovers and clarifies very important geometry and algebra.

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