Question

A sequence can be generated by using an=3a(n−1),where a1 =5 and n is a whole number greater than 1. What are the first four terms in the sequence?

Answer 1

5, 15, 45 and 135

Explanation:

Given the recursive function;

an = 3a(n-1)

If a1 = 5

a2 = 3a1

a2 = 3(5)

a2 = 15

For a3;

a3 = 3a2

a3 = 3(15)

a3 = 45

For a4;

a4 = 3a3

a4 = 3(45)

a4 = 135

Hence the first four terms are 5, 15, 45 and 135