Question

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

5,–1, –7, –13, –19, ...

A) f(n + 1) = f(n) + 6
B) f(n) = f(n +1) – 6
C) f(n +1) = f(n) – 6
D) f(n +1) = –6f(n)

Answer 1

c

Explanation:

Answer 2

Remark

Start with the ones that are wrong because they are in the wrong order.

To find F(n + 1) in a recursive formula, it must be by itself on the left. That makes B wrong.

Find out the difference in the sequence

You are subtracting 6 from the current term to get to the next term. There is no multiplication anywhere. That makes D wrong.

Now to distinguish A and C, you have to decide between addition and subtraction

You are subtracting 6 from the current term to get to the next one.

C <<<<< Answer