Quantum homework - Average Expectation Values?? Hi people, I'm struggling with my quantum mechanics homework - I've included links to photographs of my attempts at solutions, but i know they are wrong because I am given what the answers are supposed to be. Can somebody help me spot where I am going wrong? I dont have a keyboard key for psi(x) so i'll use Y(x) for wavefunctions. Here is the question: My particle, described by the wavefunction Y(x) = Ax(L-x) is confined to a region 0<x<L. A is a constant. a) Normalize the wavefunction to unity. b) Compute the average value of position <x> , <x^2> , <p> and <p^2>. Here is my solution to part a). Have i done what is being asked of me, ie. square the wavefunction, and set the integral of that, within the limits of x, equal to 1?? http://i52.photobucket.com/albums/g33/long_john_cider/normalization.jpg Here are my solutions to part B. The thing about these ones is, i dont think there is a problem with my actual calculations since I have done them a few times and got the same result. I think its with the initial equations for <x>, <x^2>, <p> and <p^2> that I start out with. <x>: http://i52.photobucket.com/albums/g33/long_john_cider/xavexpv.jpg <x^2>: http://i52.photobucket.com/albums/g33/long_john_cider/x2avexpv.jpg I am supposed to use these answers to get this result, but my answer is nowhere near: Δx = sqrt(<x^2> - <x>^2) = L / sqrt(28) <p>: http://i52.photobucket.com/albums/g33/long_john_cider/p2avexpv.jpg <p^2>: http://i52.photobucket.com/albums/g33/long_john_cider/p2avexpv.jpg I am supposed to use these answers to get this result, but again my answer is nowhere near: Δp = sqrt(<p^2> - <p>^2) = H(sqrt(10) / L where H = h/2pi , h bar in other words. Can anybody spot what I am doing wrong? I greatly appreciate any help because I have followed my notes perfectly but I am still getting the wrong answers. Thanks.