\documentclass[10pt]{article} \usepackage{graphicx, multicol,wrapfig,exscale,epsfig,fancybox,fullpage} \pagestyle{empty} \parindent=0pt \parskip=.1in \newcommand\hs{\hspace{6pt}} \begin{document} \centerline{\bf Finding Matrix Elements} \bigskip \begin{enumerate} \item Carry out the following matrix calculations. $$ \pmatrix{0&1&0\cr}\pmatrix{a_{11} & a_{12} & a_{13} \cr a_{21} & a_{22} & a_{23} \cr a_{31} & a_{32} & a_{33}\cr}\pmatrix{1\cr0\cr0\cr}$$ and $$\pmatrix{0&1&0\cr}\pmatrix{a_{11} & a_{12} & a_{13} \cr a_{21} & a_{22} & a_{23} \cr a_{31} & a_{32} & a_{33}\cr}\pmatrix{0\cr1\cr0\cr}\quad $$ \bigskip \item What matrix multiplication would you do if you wanted the answer to be $a_{13}$? \bigskip \item The bra-ket representation for the calulations in question 1 are $$\matrix{\langle2\vert A\vert 1\rangle = ? & \hbox{and} & \langle2\vert A\vert 2\rangle = ?}$$ Write question number 2 in bra-ket language. \end{enumerate} \vfill \leftline{\textit{ by Corinne Manogue \& Kerry Browne}} \leftline{copyright 2010 Corinne A. Manogue} \end{document}