HW7
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Transcript of HW7
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HW 7: MAT 312/AMS 351, SPRING 2015
In problems (1)-(4) below questions are asked about permutations
, pi S5 defined as follows: =
(1 2 3 4 52 3 1 5 4
); and pi =
(1 2 3 4 55 1 4 3 2
).
(1) Compute pi and pi. Do and pi commute?
(2) Compute 1 and pi1.
(3) Compute the cycle decomposition for both and pi.
(4)
(a) Compute the order of and the order of pi.(b) Compute 99.(c) Compute pi51.
(5) Let H denote the collection of all the following permutations in S5: id,(123)(45), (123), (54), (132), (132)(45). Give the multiplication table for H.
(6) Which permutations in problem (5) are even, and which are odd?
(7) Write the permutation (127)(35764)(265) (in S7) as a product of tran-positions.
(8) Let denote a permutation in Sn. If sgn()=-1, then show that theorder of must be odd.
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