Question

section 3: appropriate domain (questions 10–12)
choose the most appropriate domain for each situation.

1. a function models the number of books read over time.

a. {0, 1, 2, 3, …}
b. {1, 2, 3, 4, …}
c. {…, −2, −1, 0, 1, …}
d. {0, 0.5, 1, 1.5, …}

1. a function represents the amount of money earned based on the number of babysitting hours worked.

a. {0, 1, 2, 3, …}
b. {0, 0.25, 0.5, 0.75, …}
c. {…, −1, 0, 1, …}
d. {1, 2, 3, …}

Explanation:

Question 10

The domain represents time for the number of books read. Time can start at 0 (e.g., 0 hours, 0 days, etc.), and the number of books read is a non - negative integer (you can read 0 books, 1 book, 2 books, etc.). Option A is the set of non - negative integers $\{0, 1, 2, 3, \dots\}$, which is appropriate. Option B starts at 1, but time can be 0 (when no time has passed, 0 books read). Option C includes negative numbers, which don't make sense for time. Option D includes non - integer values, but the number of books read is a whole number, so non - integer time values don't correspond to a whole number of books read in a meaningful way here.

The domain represents the number of babysitting hours worked. Hours can be 0 (if you work 0 hours, you earn 0 money), and hours can be in increments of, for example, 0.25 hours (15 minutes). Option A is only whole numbers, but babysitting hours can be in fractions (like 0.25 hours). Option B is the set of non - negative numbers with a step of 0.25, which is reasonable for hours worked (you can work 0 hours, 0.25 hours, 0.5 hours, etc.). Option C includes negative numbers, which don't make sense for hours worked. Option D starts at 1, but you can work 0 hours.

Answer:

A. $\{0, 1, 2, 3, \dots\}$

Question 11