Question

STOP CLOSING MY QUESTION IM GETTING HELP



The following function defines a recursive sequence:

f(0) = -4

f(1) = 12

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

Which of the following sequences is defined by this recursive function?

-4, 12, -28, 60, ...

-4, -12, -28, -60, ...

-4, 12, -18, 54, ...

-4, 12, -18, -54, ...

Answer 1

I know its not B, because it is 12, not -12.

Answer 2

i spose .... it looked spammy at first

Answer 3

yeah, B is out

Answer 4

so the third term will settle it for us right?

Answer 5

I'm sorry, I only kept reposting because the mod kept closing it, and someone was finally helping me and they deleted it! Its so frustrating, that mod didn't want me to get help!

Answer 6

You mean option 3?

Answer 7

no, the third term is f(2) so let n=2 and work the rule

Answer 8

if its -18, then we need to determine the last term of f(3)

Answer 9

Is it D?

Answer 10

you need to work the math, afterwards the solution will be obvious

Answer 11

f(n) = -3 times f(n -1) - 2 times f(n - 2)

f(2) = -3 times f(2-1) - 2 times f(2-2) = ???

Answer 12

-18?

Answer 13

most likely

f(2) = -3 f(1) -2 f(2)
= -3(-4) -2(12)
= 12 - 24 = -12

so im most likely not reading your posted 'format' correctly

Answer 14

can you fix your math notation?

Answer 15

and of course that f(0) on the end up there, typo

Answer 16

I don't understand, are you saying I may have typed something wrong in my question?

Answer 17

I didn't type anything differently from my real question :/

Answer 18

yes. i get -12 as the 3rd term so either your options are inccorect, or i have misread the rule for f(n) since its not in a proper math notation format

Answer 19

f(n) = -3 times f(n -1) - 2 times f(n - 2)

this is confusing to try to read properly as a math equation

Answer 20

how about this:

\[f(n)=-3 x f(n-1) -2 x f(n-2)\]

Answer 21

the x aren't variables, just multiplication signs

Answer 22

let me retry this .. it could be im readingit rightand just placing values in the wrong spot

f(0) = -4

f(1) = 12

f(n) = -3 times f(n -1) - 2 times f(n - 2)

f(2) = -3 times f(2 -1) - 2 times f(2 - 2)

f(2) = -3 times f(1) - 2 times f(0)

f(2) = -3(12) - 2(-4)

-36 + 8 = -28

Answer 23

So it would be A or B

Answer 24

thats better, so we want the 3rd tern to be -28 which narrows it to one options since B is bad

Answer 25

So its A?

Answer 26

yes, id go with A

Answer 27

Thank you so much! :D

Answer 28

yep