1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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


    User Avatar
    Science Advisor
    Homework Helper

    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 :-)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook