Question

Help please!

Answer 1

Find f(5) for this sequence:

f(1) = 2 and f(2) = 4, f(n) = f(1) + f(2) + f(n - 1), for n > 2.

f(5) = ______

Answer 2

Hey @Chineseboy15 long time no see :D

Answer 3

Hello, undeadknight26. Unfortunately, I have to go to sleep now.

Answer 4

No!!!

Answer 5

Let me try to use less time to solve this question.

Answer 6

Oh snap...ur boss

Answer 7

Ah, this question perhaps is not as difficult as I thought. All right, f(n) = f(1) + f(2) + f(n - 1), can you tell me what are f(1) and f(2)?

Answer 8

2 and 4.

Answer 9

so F(n) = 2 + 4 + f(n - 1)?

Answer 10

Yes! You just say what I want to say! That is great!
Now notice n. What do you know about n?

Answer 11

it is greater than 2?

Answer 12

Yes, and 5>n. Now I think you have already known what to do next.

Answer 13

Sadly i dont :(

Answer 14

So 4 -1?

Answer 15

It is okay. Now you should replace n with 5.

Answer 16

So f(5) = 2 + 4 + f(5 - 1)?

Answer 17

2 + 4 + 4 = 10?

Answer 18

That is right!

Answer 19

You got it!

Answer 20

Wow i can't thank you enough!!!

Answer 21

You are welcome! Now I can go to sleep. Thank you for provide me another chance to help other people. See you!

Answer 22

cya!

Answer 23

@hartnn can u help me with one more question?

Answer 24

I do not know how to "generate terms"

Answer 25

Generate the first 5 terms of this sequence:

f(1) = 0 and f(2) = 1, f(n) = f(n - 1) + f(n - 2), for n > 2.

0, -1, 1, 0, 2

0, 1, 1, 2, 3

0, 1, 2, 2, 3

0, 1, 1, 2, 2

Answer 26

or should i start a new question so i can medal you?

Answer 27

f(5) is incorrect
its not 10

Answer 28

can you find f(3) first ? put n=3

Answer 29

f(3) = 2 + 4 + f(3 - 1)

Answer 30

8?

Answer 31

no , f(3-1) = f(2) = ... ?

Answer 32

f(2) = 4 = ???

Answer 33

I do not understand.

Answer 34

yes, so
f(3) = 2 + 4 + f(3 - 1) = 2+4+4 = 10
you got this ?

Answer 35

yea.

Answer 36

What do i do now?

Answer 37

similarly find f(4), by putting n=4

Answer 38

f(4) = 2+4+3 = 7?

Answer 39

why 3 ? its f(4-1) = f(3) there , right ? not just 3

Answer 40

f(4) = 2+4+f(3) = 2+4 +10 =...

Answer 41

oh i skipped lol oops..
f(4) = 2 + 4+ f(4 - 1) = 2 + 4 + 3 = 7?

Answer 42

no 9 srry

Answer 43

man, why'd you put f(3) = 3 even though you know f(3) =10 ...

Answer 44

but rn't we subtracting 1 from the 4?

Answer 45

f(4) = 2+4+f(3) = 2+4 +10 = 16?

Answer 46

like so?

Answer 47

yes,
now find f(5), put n=5
and don't put f(4) = 4, f(4) = 16

Answer 48

**put f(4) =16

Answer 49

f(5) = 2 + 4 + f(4) = 22?

Answer 50

yes! thats your f(5) = 22 correct.

Answer 51

wow thank you!!!

Answer 52

I have one more question i'll open a new thread though so u can get a medal if u help me :>

Answer 53

Generate the first 5 terms of this sequence:

f(1) = 0 and f(2) = 1, f(n) = f(n - 1) + f(n - 2), for n > 2.

0, -1, 1, 0, 2

0, 1, 1, 2, 3

0, 1, 2, 2, 3

0, 1, 1, 2, 2


put n = 3

Answer 54

i do not care for medals.

Answer 55

my medal is that you understand :)

Answer 56

Thats cool man...

Answer 57

so in f(n) = f(n - 1) + f(n - 2)
put n=3 to find f(3)

Answer 58

F(3) = f(3-1) + F(3-2)?

Answer 59

f(3) = f3?

Answer 60

F(3) = f(3-1) + F(3-2) = f(2) + f(1)
and you already know f(2) and f(1)
plug in values

Answer 61

So in this case its either b or c?

Answer 62

so its B?

Answer 63

What do u mean by plug in values? which values?

Answer 64

F(3) = f(3-1) + F(3-2) = f(2) + f(1) = 1 +0 =1
f(2) and f(1 are given in the question)

Answer 65

F(1) = 0 and F(2) = 1 right?

Answer 66

thats given in Q, and thats what i plugged in

Answer 67

so f(3) =1
what about f(4) ?
put n=4
and use f(3) =1

Answer 68

So F(4) = 2?

Answer 69

since f(4) = F(3) + f(3)?

Answer 70

im not very good at this sorry...

Answer 71

f(4) = f(2) +f(3)
right ?

Answer 72

Yes which also equals 2 right?

Answer 73

so now f(4) + f(3) = f(5)?

Answer 74

yes

Answer 75

so, f(5) = 1+2=..

Answer 76

3!

Answer 77

so far we have 0 ,1,1,3?

Answer 78

we had f(4) = 2 also!
so terms are
0,1,1,2,3
:)

Answer 79

So B was correct this whole time...

Answer 80

yes

Answer 81

as i said 7 minutes ago lol..thanks for helping me understand why though :D

Answer 82

welcome ^_^