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Homework Help: What is this?

  1. Apr 2, 2008 #1
    I have no math training beyond high school 45 years ago, and I don’t remember much of it. However I am doing a project, and I find the series below is quite valuable. But I do not know what it is or what it is called. It is like this:

    X + 1 (1/x + 1/x^2 + 1/x^3 . . . ).

    It comes ever closer to a value which is very significant in what I am doing. I wonder if someone can tell me what this is called, and what it can be used for.
  2. jcsd
  3. Apr 2, 2008 #2


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    Homework Helper

    Well what is in the brackets is a geometric progrssion
  4. Apr 2, 2008 #3


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    Science Advisor

    Yes, the part in parentheses is a geometric series that can be summed (provided the absolute value of x is bigger than 1):

    1/x + 1/x^2 + 1/x^3 + ... = 1/(x-1)
  5. Apr 3, 2008 #4
    Thank you!
  6. Apr 3, 2008 #5


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    For that sum to converge,

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