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Homework Help: Difficult Distribution Function

  1. Oct 15, 2011 #1
    1. The problem statement, all variables and given/known data

    2. Relevant equations
    F(x) = 0xf(t) dt

    3. The attempt at a solution

    The solution is 1 - e-(x/4)3

    I have tried integrating but I am not able to arrive at the solution....

    What is the indefinite integral of e-(x/4)3?
  2. jcsd
  3. Oct 15, 2011 #2


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    Science Advisor
    Homework Helper
    Gold Member

    It is hard to make out what your equations actually are. But you aren't asked to integrate e-(x/4)3. You have an x2 in there. Basically, ignoring the constants you have an integral of the form

    [tex]\int x^2e^{-x^3}\, dx[/tex]

    and you need to do a substitution similar to u = x3, du = 3x2dx but modified to include your constants.
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