Answer:
All positive integers less than or equal to 4
Step-by-step explanation:
The domain of the function are all possible values which variable x can take.
Since x is the number of times the root splits, x can take values 1 (1 time splits), 2 (2 times splits), 3 (3 times splits), 4 (4 times splits).
The variable x cannot take negative values because it cannot split -2 times.
The variable x cannot take integer values greater than 4, because this type of plant root splits 4 times while growing in the ground.
Hence, the domain of the function f(x) is all positive integers less than or equal to 4.
