Question

A sequence is defined by the recursive formula f (n + 1) = f(n) – 2. If f(1) = 18, what is f(5)?

Answer 1

f(5)=10 so 10 is your answer.

Explanation:

I just did it on ed. ;)

Answer 2

it will be easier if we wrote some terms to help us predict the nature of the sequence
f(1)=18,f(2)=18-2=16,f(3)=16-2=14,f(4)=14-2=12f(5)=10
so the nth term will be in the form
f(n)=18-2(n-1)