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August 19th, 2008, 11:36 PM   #1
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sequences and series: Arithmetic Sequences

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

And the formula to find the sum of n terms in an arithmetic sequence is Sn: n/2(2a+(n-1)d)
where a is the first term
and d is the difference
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August 20th, 2008, 01:23 AM   #2
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Re: sequences and series: Arithmetic Sequences

I don't actually know but I hope this would help you
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August 20th, 2008, 02:40 AM   #3
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The problem should have specified positive integers. The sequence (of positive integers ? n) in the problem then starts at 1 and has a common difference of 1, so the formula you gave, with a = d = 1, gives the sum of the integers 1, 2, . . . , n as n(n + 1)/2. Hence the integer value you have to find will be a little greater than the square root of 2000.
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