Chapter 3 Project

The temperature outside your home or school usually fluctuates throughout the day and night. In this project, you will record samples from the daily temperature and discuss various aspects of your data.

You will need a Calculator Based Laboratory (CBL), with temperature probe and your TI-83 Plus calculator. First, load the DAYTEMP program from the Prentice Hall companion Web site. Next, connect the TI-83 Plus calculator to the CBL that has a temperature probe in Chan 1. The program is designed to record the temperature every hour for 24 hours. It will store in the TI-83 Plus the number of hours, x, after you start the program for L3 and the temperature, y, in degrees Celsius for L4. The program will also graph the results on your calculator. Record the time that you start the program. Allow the program to run for a 24-hour period outside.

If you do not have time or equipment to collect the hourly temperatures, you may choose to use the projected hourly temperatures. A sample set of data points may also be found on the companion Web site.

Part I

Use the data collected to complete the exercises that follow. Let x be the number of hours after data collection began. Let y be the temperature in degrees Celsius.

1. Write ordered pairs for the set of data collected.

2. Use the data collected to sketch a graph of the daily temperatures. Label all points and the axes.

3. Determine the sets of numbers for the domain and range of this relation. Explain the meaning of these sets
    of numbers.

4. Does your data represent a function?

5. Does the graph have an x-intercept? If so, explain its meaning. If not, explain why not?

6. Does the graph have a y-intercept? If so, explain its meaning. If not, explain why not?

7.   a. Determine any relative minima. Where do they occur? Convert each relative minimun to time
           of day and explain its meaning.

      b. Determine the absolute minimum - the lowest temperature of the day. Is this value also a relative
           minimum? For what x-value does it occur? Convert the absolute minimum to time of day.

      c. Determine any relative maxima. Where do they occur? Convert each relative maximum to time of day
          and explain its meaning.

      d. Determine the absolute maximum - the highest temperature of the day. Is this value also a relative
          maximum? For what x-value does it occur? Convert the absolute maximum to time of day.

8. Between what x-values is the temperature increasing? Between what x-values is it decreasing? Convert the
    x-values to time of day and explain their meaning.

Part II

Now convert the temperature to Fahrenheit (to two decimal places), and repeat the previous set of exercises with your new data. Let x be the number of hours after data collection began. Let y be the temperture in degrees Fehrenheit.

1. Write ordered pairs for the set of data collected.

2. Use the data collected to sketch a graph of the daily temperatures. Label all points and the axes.

3. Determine the sets of numbers for the domain and range of this relation. Explain the meaning of these sets
    of numbers.

4. Does your data represent a function?

5. Does the graph have an x-intercept? If so, explain its meaning. If not, explain why not?

6. Does the graph have a y-intercept? If so, explain its meaning. If not, explain why not?

7.    a. Determine any relative minima. Where do they occur? Convert each relative minimum to time of day
            and explain its meaning.

       b. Determine the absolute minimum - the lowest temperature of the day. Is this value also a relative
           minimum? For what x-value does it occur? Convert the absolute minimum to time of day.

       c. Determine any relative maxima. Where do they occur? Convert each relative maximum to time of day
           and explain its meaning.

       d. Determine the absolute maximum - the highest temperature of the day. Is this value also a relative
           maximum? For what x-value does it occur? Convert the absolute maximum to time of day.

8. Between what x-values is the temperature increasing? Between what x-values is it decreasing? Convert the x-values to time of day and explain their meaning.