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Homework Help: Improper Integrals

  1. Feb 20, 2014 #1
    1. The problem statement, all variables and given/known data
    [itex]\int[/itex] (x-2)-3/2dx

    2. Relevant equations
    [itex]\int[/itex]f(x)dx from 0 to ∞ = lim (t[itex]\rightarrow[/itex]∞) [itex]\int[/itex]f(x)dx from 0 to t

    3. The attempt at a solution
    I have the solution from the solution manual, but I'm just not sure on one of the steps, after you substitute u=(x-2) and du=dx, then integrate u-3/2, but they say that the result to this step is lim(t[itex]\rightarrow[/itex]∞) -2(x-2)-1/2, that is when they integrate u-3/2 they are getting a -2 coefficient, shouldn't it be a -2/3
  2. jcsd
  3. Feb 20, 2014 #2
    Try taking the derivative of the answer to see why it is a -2.

    ##\int x^n dx = \frac{1}{n+1} x^{n+1}, n \neq -1##
  4. Feb 20, 2014 #3
    I'm ummm, I'm face palming right now, thanks.
  5. Feb 20, 2014 #4
    It's okay. Everybody has done something similar at one point or another!
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