1. Not finding help here? Sign up for a free 30min 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!

Calculate the range of S using Laplace Transform

  1. Oct 23, 2013 #1
    1. The problem statement, all variables and given/known data
    find the range of values for s: f(t)=e^(-t/2)u(t)


    2. Relevant equations



    3. The attempt at a solution
    what I did initially was to take the integral from 0 to infinity of e^(-st)e^(-t/2)u(t) dt this gave me 2/(2s+1) which when I sub in -.5 to find a divide by 0 or discontinuity then s>-.5. Then I realizeed I could do it by using the laplace transform chart so the transform of e^(-t/2)u(t) which gives s+(1/2) which gives (2s+1)/2 this is backwards from what I found earlier? I dont understand how the integral can be different from the transform but anyways if I plug in a negative .5 I would get 0 which would not be a discontinuity so it appears this way wouldnt work hmm any sugestions?
     
  2. jcsd
  3. Oct 23, 2013 #2

    gneill

    User Avatar

    Staff: Mentor

    I think you should check your transform table again. The entry for exponential decay should be of the form ##\frac{1}{s + \alpha}##
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Calculate the range of S using Laplace Transform
Loading...