A quantum-mechanical state is known to be a simultaneous eigenstate of two Hermitian operators A and

A quantum-mechanical state ψ is known to be a simultaneous eigenstate of two Hermitian operators A and B which anti commute, AB + BA = 0. What can you say about the eigenvalues of A and B for state ψ? Illustrate your point using the parity operator (which can be chosen to satisfy π = π^–1 = π^†) and the momentum operator.