All Questions from this Paper: Sigma Notation for Finding Sn from Un
Theory
MCQ
01.
Theory 8 Marks
Sigma Notation for Finding Sn from Un

Calculate the sum of the given number of terms in each arithmetic sequence.

1. Find the sum of the first 25 terms of the sequence defined by $a_n = 5n - 7$.
2. Determine the sum of the first 20 terms of the sequence defined by $a_j = \frac{3}{4} + \frac{1}{4}j$.

02.
Theory 5 Marks
Sigma Notation for Finding Sn from Un

Suppose $t_n = 3n + 2$, for $n$ being an integer.


(i) Use summation notation to express $t_1 + t_2 + t_3 + \cdots + t_{50}$.


(ii) Calculate the sum you wrote in part (i).

03.
Theory 4 Marks
Sigma Notation for Finding Sn from Un

Look at the arithmetic series $7 + 12 + 17 + 22 + \cdots + 92$:

(a) Derive the formula for the general term $t_m$ in the form $bm + c$.
(b) Using this, write the series sum using sigma notation.

04.
Theory 5 Marks
Sigma Notation for Finding Sn from Un

Look at the sum $T = \sum_{m=5}^q (3m - 2)$, where $q$ is a positive integer greater than 5:
(a) Identify the first three terms of the series.
(b) Determine the total number of terms in the series.