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$$\newcommand{\ket}[1]{|#1\rangle}$$ Compute the uncertainty, $$\Delta E$$, in energy is a state $\ket{\psi}= \alpha_1 \ket{E_1} + \alpha_2\ket{E_2}.$ Show that the uncertainty vanishes when $$E_1=E_2$$. Is this result expected? WHY?