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icystrike
Jun8-09, 08:05 AM
2008
Summation (-1)^{i} \frac{i^2+i+1}{i!}
i=1



I guess im suppose to apply the summation rule

and i got (-1)^{i} \frac{n(n+1)(n+2)+3n}{3i!}

CompuChip
Jun8-09, 12:53 PM
What summation rule are you talking about?
What is n in your final answer?
How can it depend on i anyway, if you are summing over that?

Please elaborate a bit more on how you wanted to solve the question.

icystrike
Jun9-09, 09:31 AM
What summation rule are you talking about?
What is n in your final answer?
How can it depend on i anyway, if you are summing over that?

Please elaborate a bit more on how you wanted to solve the question.

n is 2008.

Im uncertain of the application of summation - factorial.

Cyosis
Jun9-09, 09:47 AM
Could you answer CompuChip's first question? Secondly are you sure the sum is listed correctly, because when I plug it into mathematica it gives a pretty terrible result. Not something one new to summations would be expected to do.