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Integration using exponentials

  1. Oct 17, 2012 #1
    1. The problem statement, all variables and given/known data

    Screenshot2012-10-17at22915AM.png

    the integral table says when you have the above form this will be the answer:

    Screenshot2012-10-17at23832AM.png

    2. Relevant equations



    3. The attempt at a solution

    I looked at the integral table here

    http://integral-table.com/integral-table.html#SECTION00006000000000000000

    and it says erf - I don't know what that means. In any case the erf x√a does not appear in the answer. I also don't understand the step

    A√(λ/π) = A = √λ/π

    I also don't see why there is no two in the denominator.
     
  2. jcsd
  3. Oct 17, 2012 #2

    Ray Vickson

    User Avatar
    Science Advisor
    Homework Helper

    The definition of erf(x) IS include in the table.

    RGV
     
  4. Oct 17, 2012 #3
    Why is there no 2 in the denominator. I still don't know what erf means. I also don't understand the step

    A√(λ/π) = A = √λ/π
     
  5. Oct 17, 2012 #4
  6. Oct 17, 2012 #5
    Because the integral is from -∞ to ∞, not from 0 to ∞.

    It means "error function". Don't worry about that.

    You are not reading it correctly, that's why. What it reads is
    A√(π/λ) = 1
    therefore
    A = √λ/π
     
  7. Oct 17, 2012 #6
    ok, thanks for the help.
     
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