6. A quantum system is in a state u). Suppose, in this state a physical quantity which corresponds to a Hermitian operator 2 has a definite value w. Also suppose that you perform a measurement of another physical quantity which corresponds to a Hermitian operator A. Do you expect that this measurement will always result in the same outcome (that is, A has a definite value) in case a) [N, A] = 0. b) [N, A] # 0. Explain your reasoning.

6. A quantum system is in a state u). Suppose, in this state a physical quantity which corresponds to a Hermitian operator 2 has a definite value w. Also suppose that you perform a measurement of another physical quantity which corresponds to a Hermitian operator A. Do you expect that this measurement will always result in the same outcome (that is, A has a definite value) in case a) [N, A] = 0. b) [N, A] # 0. Explain your reasoning.