Question

A recursive function is shown below:

f(1) = 4 and f(n) = f(n - 1) - 8; n > 1

Which of the following lists the terms in the sequence defined by this recursive function?

4, -4, -12, -20, -28, ...

4, 4, 12, 20, 28, ...

4, 12, 20, 28, 36, ...

4, -12, -20, -28, -36, ...

Answer 1

@jim_thompson5910 Can you help me again?

Answer 2

are you familiar with the notation f(n) = f(n - 1) - 8 ?

Answer 3

no

Answer 4

f(n) is the nth term

f(n-1) is the term just before the nth term

Answer 5

I have my notes with me but they are no help

Answer 6

saying f(n) = f(n - 1) - 8 means

"nth term = (term before nth term) - 8"

Answer 7

if you are given a term, you can find the next term by subtracting 8

Answer 8

ok

Answer 9

so you would subtract 8 from 4?

Answer 10

correct

Answer 11

so it would be 4,-12,...

Answer 12

so then you would keep going ?

Answer 13

first term is 4
second term is 4-8 = -4
third term is -4-8 = -12
etc etc

notice how I'm subtracting 8 from each term

Answer 14

So it would be 4,-12,-20,-28,-36...?

Answer 15

yes

Answer 16

thank you :D

Answer 17

yw