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Homework Help: Find the integral?

  1. Jan 1, 2014 #1
    1. The problem statement, all variables and given/known data
    Find the integral of (x-4)/x^2 dx from 1 to 2.

    2. Relevant equations
    Do I divide the denominator? I got 1/x-4/x^2 from 1 to 2. But what to do next?

    3. The attempt at a solution
    The answer is ln(2)-2.
  2. jcsd
  3. Jan 1, 2014 #2
    There are multiple methods to solve this integral, but the method you chose (dividing through by the denominator) is probably the easiest. The integral of two functions added together is the sum of the individual integrals of the functions: ##\int (f(x)+g(x))dx=\int f(x)dx+\int g(x)dx##
  4. Jan 1, 2014 #3


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    Staff: Mentor

    Are you able to integrate 1/x^2 ? If so, then multiply the result by -4 and you'll have this problem half-solved.
  5. Jan 2, 2014 #4
    Can it be 1/x^2=x^-2? And I integrate from there?
  6. Jan 2, 2014 #5
    Never mind. I got it. Thanks for the help.
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