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Math Help - arithmetic progression--need help

  1. #1
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    arithmetic progression--need help

    Consider the sum of the first n integers. For what value of n will the sum first exceed 1000?

    need help
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    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by nikk View Post
    Consider the sum of the first n integers. For what value of n will the sum first exceed 1000?

    need help
    hint: the sum of the first n positive integers is given by \frac {n(n + 1)}2
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  3. #3
    MHF Contributor Mathstud28's Avatar
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    Quote Originally Posted by nikk View Post
    Consider the sum of the first n integers. For what value of n will the sum first exceed 1000?

    need help
    Solve \sum_{k=1}^{n}k=\frac{n(n+1)}{2}\geqslant 1000
    Last edited by Mathstud28; January 14th 2009 at 09:50 PM. Reason: Typo
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  4. #4
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    is it the formula both of you come from this

    Sum(n) = 1+2+3+4 ....... +n = n(n+1)/2

    ???
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  5. #5
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    my ans is = 45

    can u reconfirm it??


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  6. #6
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    The formula for summing integers from 1 to n is \frac{n(n+1)}{2}. That should get you started.

    edit: How did I miss all those posts?

    Yes OP the answer is 45
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  7. #7
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    Quote Originally Posted by Jameson View Post
    The formula for summing integers from 1 to n is \frac{n(n+1)}{2}. That should get you started.

    edit: How did I miss all those posts?

    Yes OP the answer is 45
    tq for your time
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  8. #8
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by nikk View Post
    tq for your time
    in regards to the title of this post, note that you could have derived this formula by the formula for the sum of the first n terms of an arithmetic sequence.
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