1. The problem statement, all variables and given/known data The potential energy of a particle is defined by the piecewise function: V(x) = infinity if x<0 V(x) = -V0 if 0<x<b V(x) = 0 if x>b So it's like a square well with one side being infinite. I need to find the condition on V0 and b so that no bound stationary states exist, then for there to be exactly three stationary states. 2. Relevant equations Uh.. not sure. For a regular square well, I have that if V0 > 0 there is at least one stationary state. So for there to be none, V0 has to be less than zero? But this isn't quite the same as a square well. 3. The attempt at a solution See above. I also know that each stationary state must have a node at x=0. I just don't know how to put all this together..