STEM 698 Algebra Initiative
Homework assignment due Tuesday, 4/9
1. CME Algebra page 424, Question 5
2. CME Algebra page 424, Question 6
3. CME Algebra page 434, Question 9
4. CME Algebra page 430, Question 9
5. CME Algebra p. 434 Problem 12 a - f , k, and m.
6. CME Algebra page 439, Question 2
7. CME Algebra page 445, Questions 1, 2, 3, 4
8. Rent-A-Reck Truck Rental offers a daily truck rental of $20 plus $0.25 per mile driven
that day. U-Drive-It Truck Rental offers a comparable sized truck at rate of $25 plus
$0.15 per mile driven that day.
a. Let R(x) denote the function whose input is miles driven and whose output is the cost
of renting a truck from Rent-A-Reck. Give an algebraic expression for R(x).
b. Let U(x) denote the function whose input is miles driven and whose output is the cost
of renting a truck from U-Drive-It. Give an algebraic expression for U(x).
c. Enter both of these functions into your calculator. Using the table feature determine
under what conditions it is cheaper to rent from Rent-A-Reck and under what
conditions it is cheaper to rent from U-Drive-It.
d. Repeat part c using the graphing feature of the calculator. Sketch your graph on the
coordinate axes below (or draw your own your own coordinate axes). Explain how
the graph shows under what conditions it is cheaper to rent from Rent-A-Reck and
under what conditions it is cheaper to rent from U-Drive-It.
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e. Algebraically, determine under what conditions it is cheaper to rent from Rent-AReck and under what conditions it is cheaper to rent from U-Drive-It.
f. Briefly explain how the above problem exemplifies the “Rule of Four” that Lynn told
you about.
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9. Astronauts looking at Earth from a spacecraft can see only a portion of the surface.
The fraction F of the surface of Earth that is visible at a height h, in kilometers, above the surface
is given by the function
F ( h) 
0.5h
6380  h
a. Express the fraction of the earth visible from 22000 kilometers in functional notation and
evaluate.
b. At what height is a fraction of 0.40 (i.e. 40%) of the Earth’s surface visible? Briefly
explain the approach you took to get your answer. (Hint.You can use algebra or use a
table or even a graph…)
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