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Vision - Potential
Vision Within Every Instructor - Potential Within Every Student
Newsletter of the HBCU College Algebra Reform Consortium*
Number 93, November 2009
www.ContemporaryCollegeAlgebra.org


Contents:
[1] The Importance of Seeking Out Hidden Treasures of Support [2] Polynomials [3] The Better Fit [4] Fire Hose Mathematics [5] Notices

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[1] The Importance of Seeking Out Hidden Treasures of Support

Irene Haskins

Husson University

Like many schools, Husson University runs a tutoring center where students can get help for a variety of their classes. To support our new Contemporary Algebra program, we have an adjunct instructor who teaches one section of the course and tutors in our Learning Center. Our tutors are vital to the success of many of our classes, especially Contemporary Algebra. We encourage students to use the center, but it's not always easy to convince them to actually take advantage of this valuable service. It's particularly difficult to get freshmen into the Learning Center. The majority of our students are from Maine. They come from hardworking and proud families who don't like to ask for help. Over and above that, many students erroneously associate the Learning Center with the "Special Education" rooms from their high schools. Usually, once we get students in the door and they understand what the Learning Center offers and how it can help them, they keep coming. Sadly, there's still a good number of students who really need some extra support, but don't seek help. For some of those students, Husson has a hidden treasure, in the form of one Julie Perkins. Julie is in charge of purchasing and information services for Husson's in-house and retail dining services. She's a local with a strong Down East dialect, whom the students can easily identify with. Julie has bachelor's degrees in Business and Computer Science, a MSB (Master of Business) and is working towards a Juris Doctorate. Additionally, Julie teaches classes for Husson in Ethics and Economics. She could be working a lot of other places, but stays at Husson for the students.

What Julie does for our students is provide several hours of her own time every week tutoring them in economics, business and math. Even though Julie's degrees are not in math, she has always had a knack for it and more importantly a knack for teaching others how to learn math. She tutors students in classes from basic college math to algebra, finite math and calculus. Julie volunteers several nights a week in the Learning Center, but she also tutors several hours a week in the dining hall. Many of the dining hall work study employees are "at risk" students and Julie helps them after their shifts are over. But, it's not just dining services students who come to the dining hall to meet with Julie. Students who are uncomfortable in the Learning Center will come to the dining hall instead. She also gets numerous students through word of mouth and from referrals from other dining services staff.

When Husson University adopted a Contemporary Algebra program, we inadvertently bypassed bringing Julie on board with the changes. This was an easy omission to make, because she works behind the scenes and doesn't draw attention to herself or seek acknowledgement for what she does. I knew of Julie and that she was tutoring students in math, but didn't realize the extent of her help. When the Contemporary Algebra program was being developed, a great deal of information was given to faculty throughout Husson. We had two pilot courses in the spring of 2009, but it wasn't until June or July that I realized the importance of bringing Julie up to speed with what we were doing with our Contemporary Algebra program.

I had a "special summer edition" of Contemporary Algebra for five Husson employees. Two of those employees were from dining services and Julie was helping one of them. Through that student, I heard that Julie wasn't sure where we were going with this class. Like many of us, Julie loves computations and calculations. Contemporary Algebra takes a lot of those computations away and focuses instead on concepts and context. No one had told Julie that we had dramatically changed Husson's College Algebra course, a course in which she had tutored students for many years. This situation needed to be remedied! I set up a meeting with Julie and brought her some of the articles about the need to refocus college algebra and the MAA/CRAFTY College Guidelines. I explained why Science and Humanities had made the changes to the algebra program and where we were heading. Julie was eager to hear about the new program and quickly came to understand and appreciate why the change was made. Since then, I've made sure to keep Julie in the loop. She was given her own copy of Don Small's Contemporary College Algebra text and when I put together binders of information for each of the Contemporary Algebra instructors, Julie got a copy too. Julie has a copy of the revised teacher's guide that Husson is using and I make sure she gets copies of all the activities, worksheets, quizzes and exams used in my classes. That gives her an arsenal of problems to use with the students she's tutoring. In return, Julie keeps me informed on which topics the students seem to be having the most problems with. She's also been an invaluable resource to get ideas and techniques from. Julie has been invited to our workshops, but unfortunately hasn't been able to attend one due to scheduling conflicts. She'll also be invited to meet with Don Small when he visits Husson on his way to spending Thanksgiving with his family in Maine this year.

Julie has become part of Husson's Contemporary Algebra program team and that greatly benefits our students. Because she doesn't brag about all the time she spends helping students, it would have been easy to miss her even longer. I urge others to find out if you have a hidden treasure like Julie. If you do, then make sure you bring them into the fold by keeping them informed of program changes and sharing class material to support their efforts. The same goes for those working with students and staff in tutoring centers. The more they are informed of what we're doing in classes, the more our students benefit. After all, all of us have an impact on the success of our students.

[2] Polynomial

The purpose of this exercise is to let students discover the relationships between the roots and coefficients of a quadratic polynomial equation. It is assumed that students understand the terms factor and root and their relation to one another.

Begin by computing the following:

a. Determine the quadratic equation whose roots are 2 and 3.

b. Determine the quadratic equation whose roots are $-2$ and $-3$.

c. Determine the quadratic equation whose roots are $-$2 and 3.

d. Determine the quadratic equation whose roots are 2 and $-$3.

e. Determine the quadratic equation whose roots are 0 and 2.

f. Determine the cubic equation whose roots are 0, 2, and 3.

Based on the results for parts a, b, c, and d, conjecture the relationship between the coefficients in the quadratic polynomial equation $ax^{2}+bx+c=0$ and the roots of the equation. Prove or disprove your conjecture by denoting the roots $r_{1}$ and $r_{2}$ and forming the corresponding quadratic polynomial equation.

Follow-on exercise: Experiment, conjecture, and verify the relationships between the roots and the coefficients of a cubic polynomial equation.

[3] The Better Fit

The following table showing the increase in the number of runners who finish road races appeared in the September issue of the Vision-Potential Newsletter.

Years Since
1990
No. of Finishers in
Road Races (millions)
0 4.100
5 5.951
10 7.411
15 8.101
18 9.224


Determine which of the following two linear models gives the best fit to this data and explain your reasoning.

a. $f(x)=0.28x+4.1$

b. $g(x)=0.29x+4.1$MATH

[4] Fire Hose Mathematics

The driver/operator of a fire truck needs to be adept in using mathematics. For instance, the required pressure (pounds per square inch, PSI) on a fire hose is a function of size of the hose, length of the hose, desired nozzle pressure, change in elevation from the pumper truck or hydrant, appliance (wye, siamese, ladder pipe) loss, and the flow rate (gallons per minute, GPM). Too much pressure could cause the nozzle end of the hose to "snake" endangering the fire fighters holding the nozzle. Too little pressure would reduce the nozzle pressure and thus shorten the carrying distance of the stream of water.

Answer the following questions to gain a sense of the relations between friction, flow rate, and the size and length of hose. The following data are from the Waterville, ME (Fire) Pump School.

MATH

A. Friction Loss for 100 Feet of Fire Hose

Does the friction of the water against the inside of a fire hose increase or decrease as the rate of flow (GPM) increases? Using the data in the following table, develop a suitable model for the friction loss (PSI) for a 1 1/2" fire hose and then predict the loss for a flow rate of 175 GPM. Repeat the exercise for a 2" hose.

Explain why you think your choice of model is the most suitable choice.



Friction Loss (PSI) for 100 feet of Hose
GPM 1 1/2" Hose 2" Hose
100 25 6
150 70 13.5
200 120 24
250 175 38
300 250 54
350 330 74
400 96
450 122
MATH

B. Flow Rate, Hose Size, Friction Loss

Is there a relationship between the size of a fire hose and the friction loss (PSI) for a given flow rate (GPM)? If so, develop both an exponential and a polynomial model for the relationship based on a flow rate of 100 GPM. Present an argument for which is the better model? Check your reasoning by developing similar models for flow rates of 150 and 200 GPM.

Approximate Friction Loss (PSI) for 100 feet of Fire Hose.

Flow Rate
(GPM)
Friction Loss (PSI)
Hose Size (inches)
1.5 1.75 2 2.5 4
100
25 12 6 3
150
70 30 13.5 6
200
120 50 24 10 1

MATH

[5] Notices

  1. The Joint Mathematics Meetings will be held in San Francisco, CA January 13-16, 2010. Mathematics and Education Reform (MER) will hold a special session Friday afternoon. The program will begin with a panel session, moderated by Don Small, discussing the MAA/CRAFTY College Algebra Guidelines. This will be followed by twenty minute talks given by Bill Haver (Virginia Commonwealth Univ.), Irene Haskins (Husson Univ.), Erick Hofacker (Univ. of Wisconsin at River Falls), Burnedette Turner/Donna Stallings (Lincoln Univ.), Andy Bennett/Rachel Manspeaker/ Jennifer Paulhus (Kansas State Univ.), and Barbara Edwards (Oregon State Univ.).

  2. The sixth edition of Contemporary College Algebra: Data, Functions, Modeling by Don Small is now available. Contact Kathy Kilburg (563-584-6322, Kathyj_Kilburg@mcgraw-hill.com) for an examination copy.

  3. http://usmasvdzdeanext/departments/

    math/HBCU/ is a resource website for the seventeen HBCUs in the U.S. Military Academy's program to assist HBCUs in refocusing their college algebra courses, as well as for anyone else interested in refocusing college algebra.

  4. Past issues of the Vision - Potential Newsletter are available on our website: www//ContemporaryCollegeAlgebra.org.

  5. Deadline for contributions to the January Newsletter is January 1, 2010. Opinion articles, suggestions for writing assignments, small group in-class activities, small group out-of-class projects, Queries, announcements, etc. are welcomed.

  6. Subscribe to this Newsletter

* Supported by the National Science Foundation and the U.S. Military Academy.


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