Math 331, Section 1, Fall 2016
MonWedFri 11:15 AM – 12:05 PM in LGRT 121
Professor Richard S. Ellis
Class Number 74718
 Course syllabus

Homework assignments are to be completed on the
WeBWorK system.
Detailed instructions
for using WeBWorK are available online. General
information about WeBWorK is also available online.
 My WeBWorK solutions discussed in class
 Homework Set
6 on the method of undetermined coefficients in section 2.7 of
the textbook
 Homework Set
7 on the application of second order ODEs to massspring
systems discussed in sections 2.4 and 2.8 of the textbook. As I
explained in class, I deleted problems 3 and 5 from this assignment.
 Practice problems
 Information on
quizzes and exams
 Six quizzes will be given in class. The coverage of each quiz will be announced
in advance.
 Solutions of quizzes
 Solutions of quiz
1
 Solutions of quiz
2
 Solutions of quiz
3
 Solutions of quiz 4
 Solutions of quiz 5
 Solutions of quiz 6
 The midterm exam is scheduled for Monday, October 17, 2016
from 7:00 to 8:30 PM in Goessmann 64. The exam will consist of a
number of straightforward problems that will test your
understanding of the material in chapters 1 and 2 that was
covered in class. You should also review the homework assignments
and the quizzes. The coverage of the exam is outlined online.
 The final exam
is scheduled for 10:30 AM – 12:30 PM on
Monday, December 19, in Goessmann Laboratory room 20. The exam will consist of a number
of straightforward problems that will test your understanding of
the material in chapters 1, 2, 4, and 6 that was covered in
class. You should also review the homework assignments and the
quizzes. The coverage of the exam is outlined online.
 Teaching
Assistants and Additional Help
 Handouts
 Notes on lecture
1
 Notes on
homogeneous linear ODEs of 2nd order. I wrote these notes
because the definition of the key concept of a fundamental set (or
fundamental system) of solutions on page 50 of the textbook is
nonstandard and confusing. The standard definition appears in
part (a) of Definition 3 in this document.

Method of undetermined coefficients
 The method of undetermined coefficients presented on pages
81–84 of the textbook has a serious error, which I correct
in this file. The problem arises, for example, when one tries to use the method of
undetermined coefficients to solve
y'' = x^2. Since 1 and x both solve the homogeneous equation y'' =
0, the Modification Rule in part (b) of the Choice Rules for the
Method of Undetermined Coefficients on page 81 indicates that the modified choice
for y_p should be the cubic polynomial K_2 x^2 + x^2(K_1 x + K_0). However, this is not
correct since y_p = x^4/12. The correct modified choice for
y_p should be the fourthorder polynomial x^2(K_2 x^2 +
K_1 x + K_0).
 Method of variation of parameters
 Laplace transforms

Linear algebra and Y' = AY in R^2
 Integrate
using Mathematica
 Visualize
solution curves using ODE Software.