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Multiple choice
An operator A=[3113]A = \begin{bmatrix}3 & 1 \\ 1 & 3\end{bmatrix} acts on the normalized state ψ=[1/5,2/5]|\psi\rangle = [1/\sqrt{5}, 2/\sqrt{5}]. What is the expectation value ψAψ\langle\psi|A|\psi\rangle?