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fk378
Sep15-08, 08:04 PM
1. The problem statement, all variables and given/known data
If G is a group such that (a*b)^2=(a^2)*(b^2) for all a,b in G, show that G must be abelian.


3. The attempt at a solution
First, I tried to expand the binomial (a*b)^2 and set it equal to (a^2)*(b^2). But then I didn't know where to go from there.

Dick
Sep15-08, 09:48 PM
You aren't trying very hard. A group is abelian if ab=ba for all a and b. (ab)^2=abab. (a^2)*(b^2)=aabb. Take it from there.