Question

express the sum using summation notation. use 1 as the lower limit of summation and i for the index of summation. 2 + 5 + 8 + ... + (3n - 1) 2 + 5 + 8 + ... + (3n - 1) = \sum_{\square}^{\square} \square

Explanation:

Step1: Identify the general term

The sequence terms are 2,5,8,...,(3n-1). For index \(i\), the term is \(3i - 1\) (check: \(i=1\) gives \(3(1)-1=2\), \(i=2\) gives \(5\), etc.).

Step2: Determine upper limit

The last term is \(3n - 1\), so set \(3i - 1 = 3n - 1\) → \(i = n\). Lower limit is 1.

Answer:

$$\sum_{i=1}^{n} (3i - 1)$$