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Homework Help: Laplace Transform answer

  1. Jun 5, 2012 #1
    1. The problem statement, all variables and given/known data


    3. The attempt at a solution

    I can understand step 2 to 3, but I can't get step 1 to 2. For simplicity sake we'll just call e^(3-s)t = N since it will = N anyway ultimately.

    I think the answer should be

    [N/3-s - 1/(3-s)^2)N - (0 - 1/(3-s)^2)0

    The second term is still multiplied by zero. So the answer should be infinity.
  2. jcsd
  3. Jun 5, 2012 #2
    Your variable is t. And its limits are from 0 to N. When t=0, you have

    [tex]e^{(3-s)t} = e^0 = 1[/tex]

    And not 0, as you got....
  4. Jun 5, 2012 #3
    of course, how could i have forgotten.
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