How exactly does one find a wave function? Specifically, I am asked to find the momentum space wave functoin for the nth stationary state in an infinte square well. Then I am to graph the probability density (phi sqaured) for the first and second energy levels. Lastly, I need to use the momentum space wave function to find the expectation value of p^2. For finding the expectation value, I assume that I need to integrate using p^2 as an operator between phi and phi*, just as I would if I was using the regular position wavefunction. Is this right? Anyway, what I really need help with is finding a wave function, and graphing the probability densities.