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Homework Help: Definite integral problem

  1. May 8, 2004 #1
    ive been trying to do this problem and its annoying!


    The function to be integrated: 1 + 1/x + x dx


    Interval: [8,2]

    when anti differentiating the fuction i get x + x^2/2 + lnx but i dont think the integral of 1/x is lnx...help would be appreciated
     
    Last edited: May 9, 2004
  2. jcsd
  3. May 9, 2004 #2
    1
    The function to be integrated: 1 + - + x dx
    x

    What does this mean? + - +?

    cookiemonster
     
  4. May 9, 2004 #3
    sorry updated on error
     
  5. May 9, 2004 #4
    You can separate the problem into three little ones.

    [tex]\int_2^8 \left( 1 + \frac{1}{x} + x \right) \,dx = \int_2^8 1 \, dx + \int_2^8 \frac{1}{x} \, dx + \int_2^8 x \, dx [/tex]

    And

    [tex]\int \frac{dx}{x} = \ln{|x|}[/tex]

    cookiemonster
     
  6. May 9, 2004 #5
    thanks a lot cookie. kudos goes out to you :smile:
     
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