Question

Help for a medal?!?!



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?

-4, 12, -28, 60, …

-4, -12, -28, -60, …

-4, 12, -18, 54, …

-4, 12, -18, -54, …

Answer 1

f(3)= -3 f(2) -2 f(1)
f(3) = ?
What did you get?

Answer 2

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

Answer 3

f(2) = 12
f(1) = 4
Plug in

Answer 4

Sorry, I was eating lunch. I'm not sure, I have had a difficult time trying to answer these questions. I'm confused on how to do these

Answer 5

@study100 that's right!

Answer 6

To get f(3) , plug in f(2) and f(1).
f(3) = -3 (12) - 2(4)
f(3) = ?

Answer 7

Would it be -28?

Answer 8

@study100 ?

Answer 9

@study100 ?!?!

Answer 10

@study100 ?!?!??!?!?!

Answer 11

Yes it would, sorry didn't see the notifications

Answer 12

and now that you have f(3) = -28
use it to find f(4)

Answer 13

f(4) = -3 f(3) - 2f(2)
f(4) = -3(-28) - 2(12)

Answer 14

Wow, that took a while :O

Answer 15

I'm not always online : O sorry...?

Answer 16

Everytime I tagged you you've been online. Anyways would it be 60?

Answer 17

I'm sorry, -60?

Answer 18

It shows online status, but not like "online" online

Answer 19

and what's -3 times -28

Answer 20

negative x negative = positive

Answer 21

84

Answer 22

84 - 24 = ?

Answer 23

60

Answer 24

Yes :) Answer A !

Answer 25

Thanks!

Answer 26

You're welcomed! :) Good job as well.

Answer 27

Do you mind helping with another one?

Answer 28

Sure :)

Answer 29

For the function y = f(x), what is the ordered pair for the point on the graph when x = 2m + 3?

Answer 30

@study100 ...

Answer 31

I'll take a look right away :) I'm here now.

Answer 32

Okay

Answer 33

Given:
y= f(x)
x= 2m +3

find ordered pair (x,y)
step 1: plug 2m +3 into x
so (2m+3, f(x)

step 2: now plug 2m+3 into f(x)
so (2m +3, f(2m+3))

conclusion: (2m+3, f(2m+3) )

Answer 34

Thank you!

Answer 35

You're welcomed :)