MATH 2250 Section 2 & Section 5

Fall 2011
MATH 2250 Section 2 & Section 5
Lecture Course (Math 2250-2):
Differential Equations & Linear Algebra
MTWF 7:30 AM – 8:20 AM in WEB L103
Instructor: Victor Camacho
LCB 317
[email protected]
Office Hours: TH 11:00 AM - 12:00 PM
Differential Equations & Linear Algebra
by Edwards, Henry C. & Penney, David E. (3rd ed.)
Recitation Section Course (Math 2250-5):
H 7:30 AM – 8:20 AM in WEB L103
Instructor: Nik Aksamit
LCB Loft
[email protected]
Office Hours: TBA
A grade of "C" or better in Math 2210 or Math 1260 or Math 1280 or (Math 1220 and Physics
2210 or Physics 3210). You are expected to have learned about vectors and parametric curves.
Course Outline:
This course is an introduction to differential equations, and how they are used
to model problems arising in engineering and science. Linear algebra is introduced as a tool for
analyzing systems of differential equations, as well as standard linear equations. Computer
projects will be assigned to enhance the material. We will cover most of chapters 1-10 in the
Edwards-Penney text, in addition to two supplementary sections which cover RLC electrical
circuits and additional Laplace transform material.
The course begins with first order differential equations, a subject which you touched on in
Calculus. Recall that a differential equation is an equation involving an unknown function and its
derivatives, that such equations often arise in science, and that the order of a differential equation
is defined to be the highest order derivative occurring in the equation. The goal is to understand
the solution functions to differential equations since these functions will be describing the
scientific phenomena which led to the differential equation in the first place. In chapters one and
two of Edwards-Penney we learn analytic techniques for solving certain first order DE’s, the
geometric meaning of graphs of solutions, and the numerical techniques for approximating
solutions which are motivated by this geometric interpretation. We will carefully study the
logistic population growth model from mathematical biology and various velocity-acceleration
models from physics.
We will take a four week digression from differential equations, to learn the fundamentals of
linear algebra in chapters 3-4. You need a basic understanding of this field of mathematics in
order to talk meaningfully about the theory of higher order linear DE’s and of systems of linear
DE’s. Chapter 3 starts out with matrix equations and the Gauss-Jordan method of solution. When
you see such equations in high-school algebra you might be thinking of intersecting lines in the
plane, or intersecting planes in space, or ways to balance chemical reactions, but the need to
understand generally how to solve such equations is pervasive in science. From this concrete
beginning we study abstract vector spaces in chapter 4. This abstract theory is useful not only to
the understanding of Euclidean space Rn, but it is also the framework which allows us to
understand solution spaces to systems of linear differential equations.
In Chapter 5 we will study the theory of second order and higher-order linear DE’s, and focus
on the ones which describe basic mechanical vibrations and electrical circuits. You may have
been introduced to these equations in Calculus, and we will treat them more completely now,
including a careful study of forced oscillations and resonance.
After Chapter 5 we will jump ahead to Chapter 10, the Laplace transform. This “magic”
transform converts linear differential into algebraic equations, which you can solve before
“inversetransforming”. You will have to see it in action to appreciate it. You will see, for
example, that this method gives a powerful way to study forced oscillations in the physically
important cases that the forcing terms are square waves or other discontinuous functions.
Electrical engineers often use Laplace transform techniques to understand circuits. To
successfully model more complicated physical systems like shaking in multi-story buildings,
one needs the framework of linear systems of differential equations. The linear algebra of
eigenvalues and eigenvectors is developed in chapter 6 as a tool for studying systems of DE’s in
chapter 7, where for example eigenvalues and eigenvectors will be related to fundamental modes
for mass-spring systems. We will also understand these systems of DEs from the point of view of
Laplace transforms.
Chapter 8, about matrix exponentials, shows the matrix algebra leads to beautiful formulas
for solutions to constant coefficient linear systems of differential equations. We will only cover
this chapter if time permits.
Our final course topic is Chapter 9, nonlinear systems and phenomena. This topic ties together
many different ideas, as we discuss the stability of equilibria, based on linearization, and
consider the geometry of solution trajectories in the phase portrait of autonomous systems. Many
of the most interesting (complicated) dynamical systems on earth are non-linear; perhaps the
most famous current example of this is global climate change. (We won’t be able to study that
topic in this course.
Recitation Sections:
The purpose of these extra sessions on Thursday is to work through examples and to try to clear
up any other misunderstandings in the material. In addition, the two course midterms will be
administered during these sessions.
There will be a homework assignments will all be done through WeBWork and will be due every
Thursday at 11:00 PM. The lecture notes and textbook will be very helpful in solving the
homework problems. I will assign additional practice problems that will not be graded but I
highly recommend you work through on your own. I suggest that you have access to a copy of
the textbook through the entire semester. You are encouraged to make friends and study groups
for discussing homework and practice problems, although you will each be responsible for
knowing how to complete each problem on your own (copying someone else's work will not be
productive to your learning, nor will it help you on the quizzes or exams). I will not accept late
homework under any circumstances. However, the two lowest homework grades will be
dropped from your grade.
There will be a 10 minute quiz administered at the beginning of class every Friday to test how
well you grasped the homework. In general the quiz problems will be easier than the homework
problems as they won't require as much busy work or imagination. If you anticipate not being in
class on the day of the quiz then you MUST arrange to take the quiz early. This includes athletes
and those with any other official obligations such as jury duty etc. I will not accept late quizzes
except in the event of unforeseeable medical or family emergencies for which you did not have
enough advance notice to arrange to take the quiz early. Even in these extreme cases I will still
require WRITTEN documentation. However, the two lowest quiz scores will be dropped from
your grade.
The Thursday problem sessions should be helpful to many of you. Note also that the Math
Department Lab is located in the Rushing Student Center between JWB and LCB. Initial tutorial
times will be announced. More information about the lab can be found at the Math Department
web page for undergraduates at
The Math Tutoring Center is in the Rushing Student Center, in the basement between LCB and
JWB on President's Circle. You will be able to find tutors there who can help with your math
homework. The tutoring center is open from 8:00 AM - 8:00 PM Monday through Thursday,
and 8:00 AM to 4:00 PM on Fridays. For more information about the math tutoring center visit
Computer Projects:
There will be a few computer projects assigned during the semester related to the classroom
material. They will be written in the software package MAPLE. In addition, you will be asked
to use this computer software to check various homework calculations from throughout the
course. There is a Math Department Computer Lab at which you all automatically have
accounts, and there are other labs around campus where MAPLE is also available, for example,
at the College of Engineering and the Marriot Library. There will be tutoring center support for
these projects. There will be introductory sessions to the Math Lab and to MAPLE in LCB 115
at times which will be announced during the first week of classes.
In this course you will take two in-class midterms and one final exam. Each exam is close book
though you will be allowed to use a scientific calculator. Each midterm will be taken during
your recitation section so as to not interrupt the flow of the lectures.
The exam schedule is as follows:
Midterm #1: Thursday, September 29th from 7:30 AM - 8:20 AM in WEB L103
Midterm #2: Thursday, November 10th from 7:30 AM - 8:20 AM in WEB L103
Final Exam: Thursday, December 15th from 8:00 AM - 10:00 AM in WEB L103
Grading policy: Your grade will be based on:
Final Exam
(the two lowest scores will be dropped)
(the two lowest scores will be dropped)
(20% each)
[Note: In order to receive a grade of at least "C" in the course you must earn a grade of at least
"C" on the final exam.]
Important Dates:
Last day to add:
Last day to drop:
Last day to withdraw:
August 28th
August 31st
October 24th
The Rushing Math Center offers free drop-in tutoring, a computer lab, and study areas for
undergraduates. The Rushing Student Center is in the basement adjacent to LCB and JWB. The
hours for the fall semester are:
8:00 AM – 8:00 PM Monday through Thursday
8:00 AM – 4:00 PM on Friday
Please do not behave in a way that will lessen my ability to teach or another student’s ability to
learn. Be honest about your own academic work.
ADA Statement:
The Americans with Disabilities Act requires that reasonable accommodations be provided for
students with physical, cognitive, systemic learning, and psychiatric disabilities. Please contact
me at the beginning of the semester to discuss any such accommodations that you may require
for this course.