Use summation notation to express the sum? Calculus Introduction to Integration Sigma Notation 1 Answer Wataru Nov 3, 2014 a_1+a_2+a_3+cdots+a_n=sum_{i=1}^n a_i I hope that this was helpful. Answer link Related questions How does sigma notation work? How do you use sigma notation to represent the series 1/2+1/4+1/8+…? What is sigma notation for an arithmetic series with first term a and common difference d ? How do you evaluate the sum represented by sum_(n=1)^5n/(2n+1) ? How do you evaluate the sum represented by sum_(n=1)^(8)1/(n+1) ? How do you evaluate the sum represented by sum_(n=1)^(10)n^2 ? What is sigma notation for a geometric series with first term a and common ratio r ? What is the value of 1/n sum_{k=1}^n e^{k/n} ? Question #07873 Question #117a3 See all questions in Sigma Notation Impact of this question 4984 views around the world You can reuse this answer Creative Commons License