Question

A package of cookies contains 6 cookies. Each package of cookies costs $1.49.​

A function, f(x), is written to represent the cost of purchasing x packages of cookies.

What is the practical domain for the function f(x)?
A: all positive integers
B: all real numbers
C: all whole numbers that are multiples of 6
D: all whole numbers

Answer 1

Given are 6 cookies in a package.

Given that the cost of a package = 1.49 dollars.

Let's assume we purchase 'x' numbers of packages.

So, total cost of 'x' packages = '1.49x' dollars.

f(x) is the function that represents the cost of 'x' packages, i.e. f(x) = 1.49x

Since the number of packages can not be negative or can't be decimal numbers, so 'x' should be positive integral values.

So, the practical domain of f(x) would be "positive integral values".

Hence, option A is correct, i.e. "all positive integers".