In a group, if every element has order 2 the group is abelian


Let G be a group. Prove that if x^2 = 1 for all x \in G, then G is abelian.

Note that since x^2 = 1 for all x \in G, we have x^{-1} = x. Now let a,b \in G. We have ab = (ab)^{-1} = b^{-1} a^{-1} = ba. Thus G is abelian.




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