In this activity, we will be finding missing terms in a sequence from a given formula.
Example
We can find the terms of a sequence from a formula that relates each term to its position in the sequence
The n^{th }term of a sequence is given by the formula 3n + 2
This is because the difference between the values of the terms is 3, and we multiply that by the number of the term (n) to make 3n.
Substitute | n = 1 | First term is | 3 × 1 + 2 | = | 5 | |
n = 2 | Second term is | 3 × 2 + 2 | = | 8 | ||
n = 3 | Third term is | 3 × 3 + 2 | = | 11 | ||
n = 4 | Fourth term is | 3 × 4 + 2 | = | 14 | ||
n = 5 | Fifth term is | 3 × 5 + 2 | = | 17 | ||
The first five terms are 5, 8, 11, 14 and 17
Answer
n = 1 | 5 |
n = 2 | 8 |
n = 3 | 11 |
n = 4 | 14 |
n = 5 | 17 |
Let's have a go at some questions.