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Homework Help: Proof about Expect value

  1. Jun 26, 2011 #1
    1. The problem statement, all variables and given/known data

    attachment.php?attachmentid=36736&stc=1&d=1309074422.jpg

    2. Relevant equations
    attachment.php?attachmentid=36738&stc=1&d=1309074431.jpg


    3. The attempt at a solution
    attachment.php?attachmentid=36737&stc=1&d=1309074422.jpg


    I almost get the answer as long as I can cancel out the first 2 terms.
    But they are different, what can I do now?
     

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  2. jcsd
  3. Jun 26, 2011 #2
    now you do the integral
     
  4. Jun 26, 2011 #3

    dextercioby

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    Isn't there supposed to be a minus in the Schroedinger equation ? (-hbar^2 / 2m d^2 psi / dx^2)
     
  5. Jun 26, 2011 #4
    the first term will cancel after 2 applications of integration by parts. the second term will need some adjustment with schrodinger equation and cancel out. at the end you end up with a term thatll look like the potential energy only from the schrodinger equation.
     
  6. Jun 26, 2011 #5
    i believe you can find the direct calculation on introduction to QM by griffiths, not certain though
     
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