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Anyone try this.

  1. May 18, 2004 #1
    The sum of two positive integers is 9. What is the least possible sum of their recipricols?
     
  2. jcsd
  3. May 18, 2004 #2

    matt grime

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    you can do it by listing all the possibilities, that'll show you what the general pattern is.
     
  4. May 18, 2004 #3

    mathman

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    1/4 + 1/5. The general formala simply says make the numbers as equal as possible.
     
  5. May 18, 2004 #4
    Oh man! ... mathman..I italic[jus] worked that out!!!...was about to post it!..oh well...:D
     
  6. May 20, 2004 #5

    Gokul43201

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    OR "given the perimeter of a rectangle, how do you maximize its area?"
     
  7. May 21, 2004 #6

    HallsofIvy

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    A square with each side of length perimeter/4.
     
  8. Jun 30, 2004 #7
    I guess you could write 1/x + 1/(9-x) =s, differentiate and set equal to zero getting:

    x^2 = (9-x)^2. The maximal value is x=0, and the minimal value is x=4.5, or they are the same. So 4 and 5 are the closest.
     
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