For this case we have functions of the form:
y = A * (b) ^ x
Where,
A: initial amount
b: rate of change
x: independent variable
We have two cases:
b <1: the function decreases
b> 1: the function grows.
The function that shows growth for this case is:
f (x) = 2 (3) ^ x
Answer:
f (x) = 2 (3) ^ x
