Interpreting Statements in Function Notation

4.6.1 Interpreting Statements in Function Notation

4.6.1 • Interpreting Statements in Function Notation

Warm Up

Diego is walking home from school at a constant rate. This graph represents function $d$ , which gives his distance from home, in kilometers, $m$ minutes since leaving the school.

Use the graph to find or estimate:

Line graph showing kilometers from home versus minutes since leaving school. The line starts at about 2.25 km at 0 minutes and decreases steadily to 0 km at 20 minutes, indicating travel toward home.

What is $d (0)$ , and what does it represent in the situation?

Compare your answers:

$d (0) = 2.25$ ; Zero minutes after Diego has left school, he is 2.25 kilometers from home, or Diego’s school is a little more than 2 kilometers from his house.

What is $d (12) =$

Compare your answers:

$d (12) = 0.9$

What does $d (m) = 1$ mean in the context of the problem, and what is $m$ ?

Compare your answers:

$m$ is approximately 10.5. After approximately 10.5 minutes, Diego is 1 kilometer from home.

What does $d (m) = 0$ mean in the context of the problem, and what is $m$ ?

Compare your answers:

$m$ is 20. After 20 minutes, Diego is 0 kilometers from home, or it takes Diego 20 minutes to walk the 2.25 kilometers home from school.