Invite students to share how they compared each pair of outputs. If not mentioned in students’ explanations, point out that for each pair, what we are comparing are the vertical values of the points on the graph at different horizontal values. Even though the statements don’t tell us the values of, say, $f(3)$ and $f(7)$, and the vertical axis shows no scale, we can tell from the graph that the function has a greater value when $t$ is 3 than when $t$ is 7.

Tell students that the coordinates $(0, f(0))$ represent the starting point of the drone. Ask students, “What are the coordinates of the points when the drone starts leveling off? When it starts to descend? When it lands?” ($(2, f(2)), (5,f(5))$, and $(7,f(7))$, respectively)

Highlight that the coordinates of each point on a graph of a function are $(x, f(x))$.

Discuss with students how they compared $f(t)$ and $f(t+1)$ (in the last question). Make sure students see that the $f(t+1)$ could be less than, equal to, or greater than $f(t)$, depending on the value of $t$.

• If $t$ is 2, then $t+1$ is 3. From the graph, we can see that $f(2)$ is equal to $f(3)$ because the graph has the same vertical value when $t$ is 2 and 3.
• If $t$ is 5, then $t+1$ is 6. From the graph, we can see that $f(5)$ is greater than $f(6)$ because the graph has a greater vertical value when $t$ is 5 than when $t$ is 6.