Summation sign

Summary

• Given a sequence of \(n\) numbers \(x_1,x_2,…,x_n\) , the sum of these numbers is denoted by

\[\sum_{i=1}^{n}{ x_i }\]

• \(Σ\) is called the summation symbol
• \(i\) is called the index of summation
• “ \(i=1\) ” means that the starts out equal to 1 where \(1\) is the lower bound of the summation
•   \(i\) is incremented by 1 for each successive term stopping when \(i=n\) where \(n\) is the upper bound of the summation .