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Homework Help: Wave Function

  1. Jan 29, 2009 #1
    1. The problem statement, all variables and given/known data
    Show that a wave function is phase-shifted by (pi)/2 when multiplied by
    i and by (pi) when multiplied by −1.

    2. Relevant equations

    The wave function form I am using is function = A(cos(kx-wt)+isin(kx-wt))

    But it was not specified which kind I can use

    3. The attempt at a solution
    I am not sure even where to begin...
    Last edited: Jan 29, 2009
  2. jcsd
  3. Jan 29, 2009 #2


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    I think this is not a physics question, just a mathematics one :smile:
    Phase-shifting by [itex]\phi[/itex] means replacing [tex]\psi \to e^{i \phi} \psi[/tex] ([itex]\phi[/itex] is called the phase, because the phase factor exp(i phi) only changes the argument and not the modulus of psi, so physical quantities which generally depend on [itex]|\psi|[/itex] are not affected by such a change).
    So basically what they want you to show, as far as I can tell, is that if you set phi = pi / 2 then that's the same as changing psi for i psi - which is mathematics, not physics; and very easy too.
  4. Feb 2, 2009 #3
    Thanks, I actually manged to figure it out after I posted, thank goodness. Yeah, I guess that was actually math, but it was for my wave optics class which is physics 306 so I put it here :-)
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