1. The problem statement, all variables and given/known data http://puu.sh/bTtVx/ba89b717b8.png [Broken] 2. Relevant equations I've tried using the integral method of Schrodinger's eq, getting: (X/L - (1/4pi)sin(4xpi/L) from x1 to x2. 3. The attempt at a solution I've tried plugging in the values of x given in the problem to the above equation and got reasonable answers, but they weren't right. I've tried multiple things, and I'd love to just keep trying to figure this problem out but unfortunately if I try any more I'll just miss out on the points and not bother learning it anyway (I really hate online HW systems for this reason. Puts cheating above learning the material). Also, if you have a width L, and you're finding the probability of it being in either the first third of the width, the second third of the width, or the last third of the width, why is the probability of finding it in each region not just 100/3 or 33.33%? Overall, I don't understand these probability questions much. Why can I use the generic (2/L)sin^2(pix/L) for small regions but have to do the integral of P(x) for others? Explanation would really be appreciated.