====== The Composition Of Permutations Is A Permutation ====== ==== Problem ==== Prove theorem [[Theorem:The Composition Of Permutations Is A Permutation]]. As some reminders, you may use the following facts that you proved in either Math 301 or Math 340. You may use these facts without proof. * The composition of two injective functions is injective. * The composition of two surjective functions is surjective. * A function is a bijection if it is both injective (1 to 1) and surjective (onto). Hence, the composition of two bijective functions is a bijection. * You might find induction helps you get from a composition of two bijective functions is bijective to the composition of $n$ bijective functions is bijective. ---- ==== Remarks ==== * Make remarks with a list. ---- ==== $\LaTeX$ version ==== %%%%% % DEPENDENCIES % RequiredPackages: \usepackage{tikz} % RequiredMacros: \DeclareMathOperator{\aut}{Aut} %%%%% \begin{problem} Prove theorem [[Theorem:The Composition Of Permutations Is A Permutation]]). As some reminders, you may use the following facts that you proved in either Math 301 or Math 340. You may use these facts without proof. \begin{itemize} \item The composition of two injective functions is injective. \item The composition of two surjective functions is surjective. \item A function is a bijection if it is both injective (1 to 1) and surjective (onto). Hence, the composition of two bijective functions is a bijection. \item You might find induction helps you get from a composition of two bijective functions is bijective to the composition of $n$ bijective functions is bijective. \\end{itemize} end{problem} ---- ==== External links ==== * [[wp>Dihedral group]] {{tag>problem ben}}