Question

Which recursive formula can be used to generate the sequence shown, where f(1) = 5 and n > 1?

5,–1, –7, –13, –19, ...

Answer 1

Explanation:

the sequence of numbers decrease by 6 each time, so we can write:

f(1) = 5

f(2) = -1

f(3) = -7

f(1) - f(2) = 6

or:

f(2) = f(1) - 6

which means:

f(n + 1) = f(n) - 6

Answer 2

the sequence of numbers decrease by 6 each time, so we can write:
f(1) = 5
f(2) = -1
f(3) = -7
f(1) - f(2) = 6
or:
f(2) = f(1) - 6
which means:
f(n + 1) = f(n) - 6