Before completing this portion of the lab, please start a Maple session and load the file /usr9/roxanne/LAB2/area.ms. Once this file is loaded, execute all the commands. You will need to view the plot to help you understand the following description.
The first plot shows the amount of radiation received throughout the
day on June 20, 1974 in St. Paul, Minnesota: The outer curve shows
the extraterrestrial radiation received by the outer layer of the
atmosphere directly above St. Paul, the middle curve shows the amount
of radiation that would be received by the town on a clear day and the
inner curve
shows the actual amount of radiation received by St. Paul on that
day. The units of measurement are hours of day along the x-axis and
radiation power units (calories/cm 
/min) along the y-axis.
When designing a solar heating system, it is important to know the amount of solar energy on a given day. However, when observing the three graphs, it is clear that the areas under them cannot be computed by simple geometric formulas. We will approximate their more complicated areas by using simple rectangular areas.