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Homework Help: Laplace is hurting my brain

  1. Apr 18, 2004 #1
    OK, here's the problem


    What I did:


    The book says:

    Where did the [itex]2e^{2t}\sin{t}[/itex] come from?

  2. jcsd
  3. Apr 18, 2004 #2
    Mathematica is saying that it's neither of those...

  4. Apr 18, 2004 #3


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    Homework Helper

    The cannonical form has an (s+2) in the numerator, not just s (so your invesrse transform calculation was actually incorrect). In order to account for that, you have to add another rational function that has a numerator of -2, which just happens to be (-2) times the cannonical form with sin instead of cos.
  5. Apr 19, 2004 #4
    Thanks a lot. I missed about a month of Diff Eq due to illness and an auto accident so I've been learning it all on my own. I appreciate the Q&A forum here and all those who help out.
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