Hey, I'm considering a square well which is finite on one side (left) and infinite on the other (right). So the wave function is: Left-most region: Ae^(ikx) + Be^(-ikx) Inside the well: Csin(lx) + D(cos(lx)) Right-most region: 0 where k and l are known. The problem is with boundary conditions: On the left, we have both (continuity and continuity of derivative), but on the right we only have one (continuity). So we have 3 equations to solve for 4 variables... what gives? If the context helps, I'm trying to figure out the probability that particles entering from the left in region 1 will be reflected back (i.e., the ratio of the probability flux in region 1 travelling to the left to the incident flux in region 1 traveling to the right). Any help would be greatly appreciated. Thanks, Thomas.