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Homework Help: How do I solve the integral x|x|dx?

  1. Jul 3, 2010 #1
    1. The problem statement, all variables and given/known data
    I must solve [tex]\displaystyle\int_{}^{}x|x|dx[/tex]

    How should I proceed?
     
  2. jcsd
  3. Jul 3, 2010 #2

    Hurkyl

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    I try starting with one of the first things you learned about solving problems involving |x|.
     
  4. Jul 3, 2010 #3
    You just distinguish the two cases x>=0 or x<0 and then teh calculation is straighforward. in the first case you wil have the integral of x*x and in the second you will have the integral of -x*x
     
  5. Jul 3, 2010 #4
    I wonder why Hurkyl didn't just say that in his reply... hmm...
    I guess he doesn't know how to do it... :eek:
     
  6. Jul 3, 2010 #5
    Thanks :P
     
  7. Jul 3, 2010 #6
    Are you serious?
     
  8. Jul 3, 2010 #7

    LCKurtz

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    Just guessing here, but I would say obviously no, he isn't serious. Rather it is a gentle jab at quantumjump for not giving the OP a chance to think for himself.
     
  9. Jul 3, 2010 #8
    It was either THAT, or I was totally slamming Hurkyl (but not both)!

    I prefer the Socratic method to spoon-feeding.
     
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