Abstract Algebra: Proving/Disproving |a|=|b| if |a^2|=|b^2|

tyrannosaurus
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Homework Statement



If |a^2|=|b^2|, prove or disprove that |a|=|b|.

Homework Equations


The hint I was given is that let a be an element of order 4n+2 and let the order of b=a2


The Attempt at a Solution


I can disprove this by looking at examples, such as in the group Z20 with letting a =2 and b=4, the |a|=10 and |b|=5, but |a^2|=5 and |b^2|=5. But I know that this does not disprove it for all groups, I need a more general solution. If anyone can help me on this it would be great.
 
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I'm going to go on a limb and say the statement is true for some groups (for example in Z3). When they say to disprove a conjecture, all that means is find a counterexample.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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