EXPLANATION
In order to represent the series in Sigma notation, we can apply the following standard form of a sequence:
[tex]a_n=a_1+d(n-1)[/tex]Where a_1=2, and d represent the common difference.
Computing the common difference:
5-2 = 3 8-5 = 3 11-8 = 3 14-11 = 3
Thus, the sequence is as follows:
[tex]a_n=2+3(n-1)[/tex]Applying the distributive property:
[tex]a_n=2+3n-3[/tex]Subtracting like terms:
[tex]a_n=-1+3n[/tex]Expressing in sigma notation:
[tex]\sum_{i\mathop{=}1}^53n-1[/tex]