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Homework Help: Wave equation pde problem

  1. Sep 27, 2006 #1
    Hi everyone,

    I'm having a bit of trouble with this pde problem:
    http://img243.imageshack.us/img243/9313/picture3ui3.png [Broken]

    i get the answer to be u(x,t)=0 but i am guessing thats not right.

    is the general solution to this problem: u(x,t) = f(x+ct) + g(x-ct) ??


    sarah :)
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Sep 27, 2006 #2


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    Science Advisor

    No, it's not. That would be the general solution to the homogeneous wave equation, uxx= c2utt, without a "source" term. Likewise, u(x,t)= 0 is the solution to the homogeneous equation with those conditions.

    Remember that with a linear equation, you can construct a general solution to a non-homogeneous equation by adding the general solution to the related homogeneous equation to a single specific solution to the entire equation.
  4. Sep 27, 2006 #3
    hmmm ok, i tried again and this is what i get...

    for (a) http://img291.imageshack.us/img291/6120/picture4td7.png [Broken]

    for (b) http://img301.imageshack.us/img301/5572/picture5ii4.png [Broken]

    what do you think?
    Last edited by a moderator: May 2, 2017
  5. Sep 29, 2006 #4
    lol, well i think its right anyway, thanks for the help HallsofIvy! your a legend! :D
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