Brett Frankel
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 Apr 15 reviewed Reviewed Possible arrangments Letters? Apr 15 comment Possible arrangments Letters? Welcome to math.SE. Please share your thoughts on the problem so far. Knowing what you know will help us provide the most useful hints and solutions! Apr 15 answered In S_3, an even permutation must have an odd number of orbits. True or False? Apr 15 comment In S_3, an even permutation must have an odd number of orbits. True or False? Also, most beginning texts use left actions instead of right actions, in which case you have multiplied in the wrong order. I would write $(123)=(13)(12)$, and $(12)(12)=(132)$ because I apply the rightmost permutation first. You may wish to double-check this. Apr 15 comment In S_3, an even permutation must have an odd number of orbits. True or False? You're right about $(123)$. The orbit of an element is the orbit of the subgroup generated by that element. Does that make sense? Apr 15 reviewed Reviewed High school calculus variables problem Apr 15 reviewed No Action Needed Probability of 2 independent events and 1 mutually exclusive Apr 15 reviewed Approve Probability of 2 independent events and 1 mutually exclusive Apr 14 reviewed Edit Root of unity paradox Apr 14 revised Root of unity paradox Latex Editing Apr 14 reviewed Reviewed suming an infinite series Apr 14 comment suming an infinite series Your sums are set up correctly. Hint: These are geometric series. Apr 14 reviewed Edit Cardinality, Finite Sets Proof Apr 14 revised Cardinality, Finite Sets Proof adjusted tags Apr 14 revised If $R$ is a Noetherian ring then $R[[x]]$ is also Noetherian edited body Apr 14 comment If $R$ is a Noetherian ring then $R[[x]]$ is also Noetherian @massy255 Thanks. Just fixed it! Jan 5 awarded Yearling Dec 19 awarded Nice Answer Dec 9 revised A couple questions on radical extensions added 137 characters in body Dec 9 comment A couple questions on radical extensions @user39947 Thanks for pointing out the mistake. I'll amend the post now.