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Math Help - 1/3+1/5+1/7...............=2

  1. #1
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    1/3+1/5+1/7...............=2

    hi guy's

    i need some help on making a formula for this 1/3+1/5+1/7...............=2
    i need to be able to fill in any number e.g 1/3+1/5+1/7...............=45

    thanks
    kingping
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  2. #2
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    mr fantastic's Avatar
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    Quote Originally Posted by kingping View Post
    hi guy's

    i need some help on making a formula for this 1/3+1/5+1/7...............=2
    i need to be able to fill in any number e.g 1/3+1/5+1/7...............=45

    thanks
    kingping
    There is no formula for the exact sum of the first n terms of this particular series (called a harmonic series). Your best bet is to write a simple program to sum the terms and to terminate after reaching the required sum. The output would be how many terms were summed.
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  3. #3
    Super Member Bacterius's Avatar
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    And note that usually the sum of the harmonic series will not be an integer. So you should allow input for real numbers
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  4. #4
    MHF Contributor ebaines's Avatar
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    Quote Originally Posted by Bacterius View Post
    And note that usually the sum of the harmonic series will not be an integer. So you should allow input for real numbers
    Yes - in fact, the sum of the first N terms of this series can never be an integer.
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  5. #5
    Super Member Bacterius's Avatar
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    Yes - in fact, the sum of the first N terms of this series can never be an integer.
    Where is that thanks button ?!
    Thanks for the precision though Ebaines, I would have thanked your post in normal circumstances
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