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October 3rd, 2012, 03:36 AM   #1
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Sequence and Series.

Summation of series using natural number series...

How many terms of the series 1^3 + 2^3 + 3^3 + 4^3 + ... must be taken for the sum to exceed 18 000?

Please help.
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October 3rd, 2012, 04:00 AM   #2
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Re: Sequence and Series.









Hence, we find: .
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October 3rd, 2012, 04:29 AM   #3
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Re: Sequence and Series.

Thanks Mark for answering!

But I am confused about how you got your n

from the part where n^2 + n > 268

how did you get your n from there?
Did you factorise it? if yes, please show me the steps. Thanks.
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October 3rd, 2012, 09:21 AM   #4
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Re: Sequence and Series.

No, a bit of mental calculation:



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October 4th, 2012, 01:35 AM   #5
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Re: Sequence and Series.

Thanks Mark! =)
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