In the month of September, a bird population increased by a factor of 1.25 every day for those 30 days. The function below shows the number of birds, f(x), after x days:

0 ≤ x ≤ 30

Step-by-step explanation:

In the month of September, a bird population increased by a factor of 1.25 every day for those 30 days. The function below shows the number of birds, f(x), after x days:

f(x) = 250(1.25)ˣ

Which of the following is a reasonable domain for the function?

0 ≤ x ≤ 250

0 ≤ x ≤ 30

All positive integers greater than 100

All real numbers

Solution:

Given that f(x) = 250(1.25)ˣ, where x is the number of days and f(x) is the population of the birds after x days. This means that at the beginning of the month of September (i.e. at x = 0), the population of the birds was 250. And as each day goes by, the population of the bird increases by a factor of 1.25.

The domain of a function is the set of all possible independent variables. In this case the number of days (x) is the independent variable. Since in the month of September there are 30 days, therefore the domain is:

0 ≤ x ≤ 30