Math CentralQuandaries & 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

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


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