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Homework Help: Anit derivative problem

  1. Nov 1, 2008 #1
    1. The problem statement, all variables and given/known data
    f''(x)=x^-2, x>0, f(1)= 0 f(2)=0 Find f(x)

    2. Relevant equations

    3. The attempt at a solution

    f'(x)= -x^-1 +C , f(x)= -lnx + Cx + D ... after working out i got:

    f(x)= -lnx + (ln2)x - ln2 ... does this seem correct
  2. jcsd
  3. Nov 1, 2008 #2


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    Staff Emeritus
    Science Advisor

    Well, there's an easy way to check whether something is a solution to an equation: substitute it in and see if it satisfies the differential equation!
  4. Nov 1, 2008 #3


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    Science Advisor

    Looks right to me.
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