Given the recursive function f (n) = f (n - 1) - 3; f (1) = 9, what would be the first three terms of the sequence?

The first three terms of sequence are 9, 6, 3

Solution:

Given the recursive function f (n) = f (n - 1) - 3

Where f (1) = 9

To find: First three terms of sequence

Substitute n = 2, n = 3 and n = 4 in given recursive function

When n = 2

f (n) = f (n - 1) - 3

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

f (2) = f (1) - 3

f (2) = 9 - 3 = 6

f (2) = 6

Thus second term is 6

When n = 3

f (3) = f (3 - 1) - 3

f (3) = f (2) - 3

f (3) = 6 - 3 = 3

f (3) = 3

Thus the third term is 3

When n = 4

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

f (4) = f (3) - 3

f (4) = 3 - 3

f (4) = 0

Thus the fourth term is 0

Thus first three terms of sequence are 9, 6, 3