0 Comments
Recursion means defining something, such as a function, in terms of itself. So Y = {9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99, ... }
Let f (0) = 0
So f ( n + 1) = f (n) + 9
f (1) = f(0) + 9 = 0 +9 = 9
f (2) = f(1) + 9 = 9 +9 = 18
9.4m questions
12.2m answers