You are deciding whether to light a new factory using bulb A, bulb B, or bulb C. Which bulb would be better to use on the factory floor?
Which bulb would be better to use in the break room?
To answer these questions, you will compare the energy usage of the three bulbs. The amount of energy the lights use is measured in units of kilowatt-hours. A kilowatt-hour is the amount of energy needed to provide 1000 watts of power for 1 hour.

1. Circle the two bulbs you picked.

2.

3. Practice: Summarizing (3 points)
Fill in the blanks.

The energy usage of a light bulb is a function. The input for the function is , measured in hours.

The output of the function is energy usage, measured in .

Identify the functional relationship between the variables. is a function of .

The graph of the function will show energy usage on the axis and time on the axis.
4. Practice: Organizing Information (2 points)
Use the data given to complete the table for your first bulb.
DATA TABLE A
Time (hours)
x Energy (kWh)
y Point (time, energy)
(x, y)
3
10
5. Practice: Organizing Information (2 points)
Use the data given to complete the table for your second bulb.
DATA TABLE B
Time (hours)
x Energy (kWh)
y Point (time, energy)
(x, y)
3
10
6. Practice: Organizing Information (5 points: 1 point for labels, 2 points for each graph)

Label the axes of the graph with "Time (hours)" and "Energy (kWh)." Plot the points from table A on the graph. Connect the points with a line. On the same graph, plot the points from table B and connect them with a line.

7. Practice: Summarizing (1 point)
Classify each of your graphs as increasing, decreasing, or constant.

First bulb:

Second bulb:

8. Practice: Summarizing (2 points)
Fill in the blanks.

First bulb: When 3 is the input, the output is . When 10 is the input, the output is .

Second bulb: When 3 is the input, the output is . When 10 is the input, the output is .

9. Practice: Summarizing (1 point)
The workers leave the lights on in the break room for stretches of about 3 hours. Which light bulb would light this room using the least amount of energy?

10. Practice: Summarizing (1 point)
The lights in the main room of the factory stay on for stretches of 9 hours. Which kind of light bulb would light this room with the least amount of energy?