Difference between revisions of "Elementary symmetric sum"

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== Definition ==
 
== Definition ==
  
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== Uses ==
 
== Uses ==
  
Symmetric sums show up in [[Vieta's formula]]
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Symmetric sums show up in [[Vieta's formulas]]

Revision as of 14:14, 18 June 2006

Definition

The nth symmetric sum is the sum of a group of numbers, taken n at a time. So if the numbers are a, b, c, and d, then:

1st Symmetric Sum = a+b+c+d

2nd Symmetric Sum = ab+ac+ad+bc+bd+cd

3rd Symmetric Sum = abc+abd+acd+bcd

4th Symmetric Sum = abcd


Uses

Symmetric sums show up in Vieta's formulas