====== Number Of Permutations ====== ==== Problem ==== Given finite set $X$ with $n$ elements, how many permutations are there of $X$? - Show that if $X=\{1\}$, then there is only one permutation of $X$. - Show that if $X=\{1,2\}$, then there are two permutations of $X$. List them. - Make a list of all permutations of $X=\{1,2,3\}$, and then of $X=\{1,2,3,4\}$. What pattern do you see? - Make a conjecture about the number of permutation of $X$ if $|X|=n$. Then prove your conjecture. ---- ==== Remarks ==== * Make remarks with a list. ---- ==== $\LaTeX$ version ==== %%%%% % DEPENDENCIES % RequiredPackages: \usepackage{tikz} % RequiredMacros: \DeclareMathOperator{\aut}{Aut} %%%%% \begin{problem} Given finite set $X$ with $n$ elements, how many permutations are there of $X$? \begin{enumerate} Show that if $X=\{1\}$, then there is only one permutation of $X$. \item Show that if $X=\{1,2\}$, then there are two permutations of $X$. List them. \item Make a list of all permutations of $X=\{1,2,3\}$, and then of $X=\{1,2,3,4\}$. What pattern do you see? \item Make a conjecture about the number of permutation of $X$ if $|X|=n$. Then prove your conjecture. \end{problem} ---- ==== External links ==== * [[wp>Dihedral group]] {{tag>problem ben}}