Sum of order: 1*2 + 2*3+ 3*4+....+ 999*1000

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japiga
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Re: Sum of order: 1*2 + 2*3+ 3*4+....+ 999*1000

Postby japiga » Wed Sep 22, 2010 2:10 pm

1^2+2^2+3^2…..+ 999^2 . How to put this sum in the simple mathematic formula? Since, only 999^2 = 998001and imagine total sum: + 998^2 + 997^2 + 996^2 + ... + 1. I hope that now is more clear what I actually need. Thanks a lot!

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Martingale
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Re: Sum of order: 1*2 + 2*3+ 3*4+....+ 999*1000

Postby Martingale » Wed Sep 22, 2010 2:16 pm

japiga wrote:1^2+2^2+3^2…..+ 999^2 . How to put this sum in the simple mathematic formula? Since, only 999^2 = 998001and imagine total sum: + 998^2 + 997^2 + 996^2 + ... + 1. I hope that now is more clear what I actually need. Thanks a lot!


I've given you the formula for the sum of the squares of the first 999 natural numbers...ie




If I say any more I will be giving you the answer..is that what you are wanting me to do?

japiga
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Re: Sum of order: 1*2 + 2*3+ 3*4+....+ 999*1000

Postby japiga » Wed Sep 22, 2010 2:26 pm

Do you think that this assignment is finished if I accept this and moreover if my teacher accept it? Is there more mathematic approach and more predictable the final result of this “quadratic” sum? Since first sum (1+2+3+…+999) is more clear how to reach the final result!

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Martingale
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Re: Sum of order: 1*2 + 2*3+ 3*4+....+ 999*1000

Postby Martingale » Wed Sep 22, 2010 2:33 pm

japiga wrote:Do you think that this assignment is finished if I accept this and moreover if my teacher accept it? Is there more mathematic approach and more predictable the final result of this “quadratic” sum? Since first sum (1+2+3+…+999) is more clear how to reach the final result!


Sorry, but I really don't understand what you are trying to say.

I'll leave you with this..


if I wanted

I would use the formula with to get


japiga
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Re: Sum of order: 1*2 + 2*3+ 3*4+....+ 999*1000

Postby japiga » Thu Sep 23, 2010 8:03 am

Now, it's OK. I understood. It sounds very simple. Thanks a lot. This is great way of communication and very quick tool for maths problem solving! Be in touch. Regards


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