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Need some help with solving diff.equ with matlab/simulink

  1. Feb 9, 2009 #1

    1. The problem statement, all variables and given/known data
    I have this x'[t] + x[t] = a + Sin[b*t] diff.equ that I would like to solve with matlab/simulink.
    Let set a=1, b=1 and

    2. Relevant equations
    I know that x(t) = 1/2 e^-t (-cos(t) e^t+sin(t) e^t+2 e^t+3) and what it look like (see pic). I aslo got the transfer equ G(s) from Laplace and it should be:

    G(s) = (a/s+b/(b^2+s^2))/(s+1),

    3. The attempt at a solution

    The only thing I dont get right is the initial value as you can see at the pic. It also shows what it should look like. What do I do wrong?

    It should be easier to use the transfer equ G(s), but I dont get that right either. Any suggestions?

    http://img205.imageshack.us/img205/821/reglerth3.jpg [Broken]

    Thank you!
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Feb 9, 2009 #2
    Ah dont worry guys, I fixed it
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