SEARCH HOME
 Math Central Quandaries & Queries
 Question from Kenneth: What would be used for the top and bottom indices for the sigma sign in my example shown below? If the amounts were 1 + 2 + 3, the top index would be 3 and the bottom would be i = 1, but if the amounts are 1 + 2 + 4, or 1 + 0.05 + 1/3, what would the indices be since these amounts are in an uneven pattern. $\sum_{?}^{?} =1+2+4.$ I thank you for your reply and explanation

Hi Kenneth,

I would use set notation and say

$\sum_{i \in S} i \; \; \mbox{ for S={1,2,4} }$

Harley

Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.