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#1 2010-03-20 17:05:17
- soha
- Real Member
- Registered: 2006-07-07
- Posts: 2,530
Simplify
Expand and simplify : ∑x ²+ 2 ∑ yz
"Let us realize that: the privilege to work is a gift, the power to work is a blessing, the love of work is success!" 
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#2 2010-03-20 18:37:47
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Simplify
Hi soha;
I can do the first sum by indefinite summation, the second sum I need to know what variable to sum in terms of.
If we are doing it in terms of x then using indefinite summation rules.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#3 2010-03-21 03:07:00
- soha
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- Registered: 2006-07-07
- Posts: 2,530
Re: Simplify
how did you get that 12?
"Let us realize that: the privilege to work is a gift, the power to work is a blessing, the love of work is success!"
- David O. McKay
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#4 2010-03-21 10:06:35
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Simplify
Hi soha;
I made some assumptions to get that. Indefinite summation requires an understanding of the so called factorial powers. The summation calculus is a little advanced. What grade are you in and is that the exact question?
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#5 2010-03-21 20:20:57
- soha
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- Registered: 2006-07-07
- Posts: 2,530
Re: Simplify
Doesnt that come under cyclic symmetry?
"Let us realize that: the privilege to work is a gift, the power to work is a blessing, the love of work is success!"
- David O. McKay
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#6 2010-03-21 22:33:57
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Simplify
Hi soha;
I am not sure as to what cyclic symmetry is? See post #4.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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