Given that ,
"\\sigma=\\begin{bmatrix}\n 3&4&5&2&1 \\\\\n 1&2&3&4&5\n\\end{bmatrix},\\gamma =\\begin{bmatrix}\n 5&3&2&4&1 \\\\\n 1&2&3&4&5\n\\end{bmatrix} \\in S_7"
"\\sigma\\gamma=\\begin{bmatrix}\n 3&4&5&2&1 \\\\\n 1&2&3&4&5\n\\end{bmatrix}\\begin{bmatrix}\n 5&3&2&4&1\\\\\n 1&2&3&4&5\n\\end{bmatrix}"
"=\\begin{bmatrix}\n 1&2&3&4&5 \\\\\n 3&1&4&2&5\n\\end{bmatrix}" "=(1 \\ 3 \\ 4 \\ 2)" .
"=(1 \\ 2)(1 \\ 4)(1 \\ 3)"
Since we know that every permutation in "S_n,n>1," is a product of 2-cycles. However, the decomposition of a permutation into a product of two cycles is not unique, but the number of 2-cycles is equal in every decomposition,
i.e., if"\\, \\alpha=\\beta_1.\\beta_2.......\\beta_r \\ \\ and \\ \\alpha=\\gamma_2.\\gamma_2............\\gamma_s"
where "\\beta's \\ and \\ the \\ \\gamma's" are 2-cycles.
Then "r=s" .
Also we know that a permutation can be expressed as a product of an odd number of 2-cycles is called an odd permutation.
Hence by definition, "\\sigma\\gamma" is an odd permutation.
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