Question

Given the sequence -3, 9, -27, 81, -243, ..., find the recursive formula.

Answer 1

Answer:

$a_{n}$ = - 3$a_{n-1}$

Step-by-step explanation:

There is a common ratio between consecutive terms of the sequence, that is

r = 9 ÷ - 3 = - 27 ÷ 9 = 81 ÷ - 27 = - 243 ÷ 81 = - 3

The recursive formula is of the form

$a_{n}$ = r$a_{n-1}$ = - 3$a_{n-1}$