7. Definition of Sigma Notation Consider the following addition : Based on the patterns of the addends, the addition above can be written in the following form 2 + 5 + 8 + 11 + 14 = (3(1) – 1) + (3(2) – 1) + (3(3) – 1) + (3(4) – 1) + (3(5) – 1) + (3(6) – 1) 2 + 5 + 8 + 11 + 14
8. The amount of the term in the addition above can be written as (3i – 1). The term in the addition are obtained by substituting the value of i with the value of 1, 2, 3, 4, and 5 to (3i – 1) The symbol read as sigma, is used to simplify the expression of the addition of number with certain patterns. In order that you understand more, the addition above can be written as : = 2 + 5 + 8 + 11 + 14 =(3(1) – 1) + (3(2) – 1) + (3(3) – 1) + (3(4) – 1) + (3(5) – 1) + (3(6)-1) =(3(1) – 1) + (3(2) – 1) + … + (3(i) – 1) + … + (3(6)-1)