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Homework Help: Integrating Dirac Delta

  1. Sep 16, 2011 #1
    1. The problem statement, all variables and given/known data

    Integrate exp[abs(x)+3]*delta(x-2) dx, -1, 1

    2. The attempt at a solution

    f(x)=exp[abs(x)+3]*delta(x-2)
    f(2)=148.4
    Integrate exp[abs(x)+3]*delta(x-2) dx, -1, 1 = 0

    3. Why is the answer 0?
     
  2. jcsd
  3. Sep 16, 2011 #2

    Hootenanny

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    Because the point x=2 does not lie in your domain of integration and your integrand vanishes at every other point.
     
  4. Sep 17, 2011 #3
    Note that dirac delta function is zero if its argument is nonzero. The integration interval <-1;1> does not contain point x=2, where the dirac delta function is only nonzero.
     
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