1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution I'm fine with parts a) and b) However I don't understand what part c) is asking me to do. How do I 'measure' an operator? There are only two things I can think to do: 1. Find the expectation values of A for <Φ1|A|Φ1> and <Φ2|A|Φ2> or 2. Find the operator eigenvalues of A I know how to perform these tasks, so the only thing I'm confused about is the wording. I don't really understand what is meant when it talks about 'measuring' an operator. Thanks.