Elementary symmetric sum

Revision as of 14:13, 18 June 2006 by Mysmartmouth (talk | contribs)

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 formula