Question

FAN AND MEDAL!!!!! PLEASE HELP!!!!!
The following function defines a recursive sequence:

f(0) = -4

f(1) = 12

f(n) = -3•f(n -1) - 2•f(n - 2); for n > 1

Which of the following sequences is defined by this recursive function?
A) -4, 12, -28, 60, …
B) -4, -12, -28, -60, …
C) -4, 12, -18, 54, …
D) -4, 12, -18, -54, …

Answer 1

B

Answer 2

B can't be the answer. @Pandemonium

Answer 3

no wait let me fix this real quick

Answer 4

okay

Answer 5

i got C but id check with someone else to be sure

Answer 6

Please explain how you got the answer

Answer 7

So did you just guess?

Answer 8

No my teacher is here helping me and even he's confused what the question is asking but he's trying different methods to find the answer

Answer 9

okay

Answer 10

It's florida virtual school, so I wouldn't be surprised if it was entirely wrong.

Answer 11

@pooja195 please help

Answer 12

yea, but me him decide to eliminate the worst possible answers and we got rid of A and B

Answer 13

okay thx

Answer 14

so your left with C and D

Answer 15

ok,
f(0) = -3 , first term = -3

f(1) = 6, 2nd term = 6
so, as of now our sequence is -3,6

to find nect term, we will use
f(n) = -2•f(n -1) - f(n - 2)

put n= 2 here, what do u get ?

Answer 16

-2, but that must be wrong

Answer 17

you just replace "n" by "2" there,
to get f(2)

Answer 18

f(2) = -2 f(1) - f(0)

and you already know
f(1) =6, f(0) = -3
just plug in values!

Answer 19

you need to find f(3) too!
f(3) = - 2f(2) - f(1) = - 2(-9) -6 = 18-6 = 12

Answer 20

That's what I did. Idk how I got such a bogus answer. What did you get?

Answer 21

Well A isnt matching and B isnt either

Answer 22

Can you do it for f(4)? I'd probably get it wrong

Answer 23

no that'll probably mess it up but u can try and see if u find a good answer

Answer 24

okay

Answer 25

ok

Answer 26

I got -13, but it's obviously wrong

Answer 27

yea, well my best possible answer would have to be D

Answer 28

really, why?

Answer 29

its the only one close to matching what me and my teacher got but to sure try to find other possible solutions

Answer 30

ok

Answer 31

so yea its either gonna be C or D

Answer 32

my best guess would be D but i aint 100% sure