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Homework Help: Proving time independence of energy eigenstates

  1. Dec 1, 2009 #1
    1. The problem statement, all variables and given/known data
    We are ask to find the probability density of psi(x,t). I know that psi have an exp term but i don't understand how by squaring psi make the exp term disappear.

    2. Relevant equations
    Psi = sqrt(2/L)sin(n*pi*x / L)e^(-2*pi* i(E/h)t

    3. The attempt at a solution
    I attempted changing the exp term into polar coord but I cant seem to get anywhere with that.
  2. jcsd
  3. Dec 1, 2009 #2


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    Homework Helper

    You don't square psi. You multiply it by it's complex conjugate. Makes all the difference.
  4. Dec 1, 2009 #3
    Yes, I just read my text and I discover you are suppose to multiple the complex conjugate. Thank you.
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