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.

Alumni Liaison

Prof. Math. Ohio State and Associate Dean
Outstanding Alumnus Purdue Math 2008

Jeff McNeal