Commutator of \bgroup\color{black}$E$\egroup and \bgroup\color{black}$x$\egroup

Again use the crutch of keeping a wave function on the right to avoid mistakes.

\begin{eqnarray*}[E,x]\psi(x,t)&=&\left(i\hbar{\partial\over \partial t}x-xi\hba...
...ial t}-i\hbar x{\partial\over \partial t}\right)\psi(x,t) =0 \\
\end{eqnarray*}


Since \bgroup\color{black}${\partial x\over \partial t}=0$\egroup.



Jim Branson 2013-04-22