Question

Find f(5) for this sequence:

f(1) = 2 and f(2) = 5, f(n) = f(1) + f(2) + f(n - 1), for n > 2.

f(5) = ______

Answer 1

@jigglypuff314

Answer 2

ok so f(5) = f(1) + f(2) + f(n-1)
and
f(n-1) = f(1) + f(2) + f(n-2)
ok?

Answer 3

and 5>2 so we can say f(5) = f(1) + f(2) + f(4)
ok?

Answer 4

ok

Answer 5

ok so
f(5) = f(1) + f(2) + f(4)

what else?

Answer 6

well and what is f(4)

Answer 7

oh and f(1) = 2 f(2) = 5
2 + 5 + f(4)


f(4) is 12 im guessing

Answer 8

f(4) = 2 + 5 + f(3) and f(3) = f(1) + f(2) + f(2) = 2 + 5 + 5 = 12
so f(4) = 2 + 5 + 12 = 19

Answer 9

so f(4) = 19 not 12

Answer 10

so 2 + 5 + f(4) = ?

Answer 11

2 + 5 + 19 = 26

Answer 12

yes :)
got it?

Answer 13

yes, thank you :)

Answer 14

you're welcome ;)