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: 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

    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


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    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.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook