Thread: Need help with showing that orders of elements are equal...

1. Need help with showing that orders of elements are equal...

I need some help from some of the algebraists on the board.

I have the following problem... I have tried so many ways to prove it but I just can't seem to get there.

The Problem is:

Let G be a group with a,b in G. Prove that b and aba^(-1) have the same order.

I have attempted to show for finite order and infinite order, but no matter what i do I can't see it... Any help would be greatly appreciated...

Thanks!!!

2. Originally Posted by ginafara
I need some help from some of the algebraists on the board.

I have the following problem... I have tried so many ways to prove it but I just can't seem to get there.

The Problem is:

Let G be a group with a,b in G. Prove that b and aba^(-1) have the same order.
Say $\mbox{ord}(b) = n$. Then $(aba^{-1})^n = ab^na^{-1} = aea^{-1} = e$. Now argue that $n$ is the smallest exponent for $aba^{-1}$.