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: Inverse Laplace transform (Initial Value Problem)

  1. Sep 21, 2013 #1
    1. The problem statement, all variables and given/known data

    I'm stuck trying to find out the inverse Laplace of F(s) to get y(t) (the solution for the differential equation):

    Y(s) = 1 / [ (s-1)^2 + 1 ]^2

    3. The attempt at a solution

    I tried using a translation theorem and then apply the sine formula, but the denominator is still all squared. I also tried partial fractions to expand Y(s) but I didn't get it right...

    Any suggestions please?
  2. jcsd
  3. Sep 21, 2013 #2

    Ray Vickson

    User Avatar
    Science Advisor
    Homework Helper

    Yes: show us what you did and what you got. How can we possibly help if we have no idea of what your problem is?
  4. Sep 21, 2013 #3

    Therefore, [tex]\left[\frac{1}{ (s-1-i)(s-1+i) }\right]^2=\left[\frac{1}{2i}\left(\frac{1}{s-1-i}-\frac{1}{s-1+i} \right ) \right ]^2[/tex]

    Can you continue it from there?
  5. Sep 22, 2013 #4

    My friend, that's the thing, I can't get past that. I stated the problem clearly: "I'm stuck trying to find out the INVERSE LAPLACE of the given Y(s) to get y(t)". There's no point in showing what I did before, it's not needed for what's after the equation I posted.

    Anyway, I got it. It was just applying one of the formulas from the Laplace transform tables. I thought partial fractions or something else had to be done.

    Thanks for your help
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted