Question

The function ​f(x)​ is the height of a model rocket x seconds after launch.

The rocket reaches its maximum height in 2.5 seconds and hits the ground at 5 seconds.
What is the practical domain for the function f(x)?
[0, 5]
whole numbers in [0, 5]

all real numbers

all integers in ​ [0, 5]

Answer 1

all real numbers in [0, 5]

or just [0, 5]

Explanation:

The domain is all of the possible values for the independent variable, or x-values. For this problem, it is the time in seconds.

The information we are given about seconds is:

2.5s to reach max. height

5s to hit ground

We assume it starts at 0s

The domain must include the values 0, 2.5, and 5.

Whole numbers are non-partial numbers starting 0 counting up.

Integers are non-partial numbers, positive and negative, and includes 0.

Real numbers are all partial and non-partial numbers, positive and negative.

Since the domain must include 2.5, a partial number, the domain must be real numbers. The rocket launches at 0s and stops flying after 5s, so the domain is between 0 and 5.

Domain is all real numbers in [0, 5]