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?

Question

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?

anonymous · Answer

choices are:

 -4, 12, -28, 60, … 
-4, -12, -28, -60, … 
-4, 12, -18, 54, …
 -4, 12, -18, -54, …

anonymous · Answer

@vangoo98 sorry to bother you but could you help me out on this one too please?

anonymous · Answer

I have no idea tbh o.e
I haven't gotten to recursive functions yet.
Sorry v.v
What grade are you in btw?

freckles · Answer

try entering in 2 for n

anonymous · Answer

Its okay. do you know anyone that might be able to help me out on this one though? and I am a 10th grader but I am also taking 9th grade math because I fell behind in the school system @vangoo98

freckles · Answer

f(n) = -3•f(n -1) - 2•f(n - 2)
f(2)= -3*f(2-1)-2*f(2-2)
f(2)=-3*f(1)-2f(0)
f(1) is given and so is f(0)

anonymous · Answer

Oh, I'm in 10th too, and I haven't gotten to this lol. And I gotcha
And maybe @texaschic101

freckles · Answer

replace f(1) with 12 
and replace f(0) with -4

anonymous · Answer

Thanks so much :) and @freckles I am confused on what you said :/

freckles · Answer

may i ask on which part

anonymous · Answer

The beginning.. I am really confused on how to do this

freckles · Answer

I replaced n with 2

freckles · Answer

because we didn't have f(2) yet
but we have f(1) and f(0)

anonymous · Answer

so like what you had did: f(n) = -3•f(n -1) - 2•f(n - 2)
f(2)= -3*f(2-1)-2*f(2-2)
f(2)=-3*f(1)-2f(0)
f(1) is given and so is f(0)
so do we just plug in the f(1) and also the f(0)?

freckles · Answer

yes

freckles · Answer

replace f(1) with 12 and f(0) with -4

freckles · Answer

these values were given

freckles · Answer

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

anonymous · Answer

so I take that ^ and solve it to get the answer?

freckles · Answer

your answers are given in the form 
f(0),f(1),f(2),f(3),...
f(0) is the 1st term
f(1) is the 2nd term
f(2) is the 3rd term
f(3) is the 4th term

freckles · Answer

so evaluating that will give you your third term

anonymous · Answer

so then would it be B then?

freckles · Answer

why do you think it is B?

freckles · Answer

Isn't your first two terms... -4,12,
not -4,-12

anonymous · Answer

A?