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) = ______

Numerical Answers Expected!

Answer for Blank 1:

Please help me i forgot how to do this lolol

Answer 1

they tell you
f(n)= f(1) + f(2) + f(n-1)

f(1) + f(2) will always be 2+5= 7, so the rule can be written
f(n)= f(n-1) + 7

that says: if you know f(n-1), then the next number is found by adding 7
so
f(3) = f(2)+7
f(2) is 5, so f(3)= 5+7= 12
so we know f(3)= 12
now find f(4)= f(3)+7 = 12+7= 19
now find f(5)
can you do that ?