Differential Equations
Math 244, Fall 2022

Textbook

Image for textbook

Image for textbook

Same book as last semester. There are a couple of different versions of the 9th edition (see below).

Elementary Differential Equations and Boundary Value Problems, by William Boyce and Richard DiPrima (9th Edition)

TEXT NOTE: This is NOT the current version, which is the 11th edition. There are a couple of different versions of the text; here are the links to Amazon.com for the information:
With Boundary Value Problems
The text without Boundary Value Problems
There also is an optional Student Solution Manual Available (typically, these have more detailed solutions to odd numbered problems)
We'll generally be covering topics from Chapters 1-7 except Chapter 4. Also, topics from Chapter 7, 9 as time permits.

Beginning Material

Syllabus
Course Calendar
Homework for Day 1-2
Homework to Exam 1
Homework to Exam 2
Homework to Exam 3 NOTE the change of the date for Exam 3 (to Friday instead of Monday).

Links by Week and Section

Video lectures
Review Material - Read these at your leisure.

Chapter 1
- Slides for Day 2
- Direction Fields example
Chapter 3
Section 3.8 (Spring-Mass system with periodic forcing)
- (PDF) How to use Exponentials in place of Sine and Cosine
- (PDF) Notes to replace Section 3.8
- Solutions to the exercises at the end of the 3.8 handout
- (Youtube clip) Video from MIT- Beating and Resonance (About 2 minutes)
- Watch a wine glass shatter. (Less than 1 minute)
- (Youtube clip) The Tacoma Narrows Bridge Collapse (Or was it resonance?) (About 6 minutes)
- (Youtube) Film from 1969 with Prof. Miller (About 14 minutes total)
- (Youtube) - Just for fun.
Week 13 Links (Nov 28 - Dec 02): We're going through a ``simplified'' version of Chapter 7 and 9 in the time remaining. If you have had linear algebra, you might go to the text to read about the general theory- In class, we're going to restrict ourselves to the plane (two dimensional systems).
- Notes to Replace 7.1
- Notes to Replace 7.2
- Notes to Replace 7.3-7.5
- How to Sketch Solutions
  - Video 1: Summary so far
  - Video 2: Sketching solutions (Sorry for running off the edge- It does come back).
  - Video 3: More sketching solutions
Week 14 Links (Dec 05 - Dec 09):
- Complex Eigenvalues/vectors
- Double Root:
  - (Video) A Single Eigenvalue (and summary) (An error was made and then repeated about 0:30- The trace is 2 for both matrices).
  - (PDF) Notes
  - (PDF) Homework
- Poincare Diagram:

Exam Links

Exam 1 Links

Exam 2 (Section 3.8 won't appear on the exam)

Summary of topics for Exam 2
Sample questions
Sample solutions (Now posted!)
Section 3.7 Handout
Section 3.7 Solutions (Section 3.8 will not be on the exam).

Exam 3 (Section 3.8 won't appear on the exam)

Topics for the exam
Sample questions (Question 19 corrected - The table entry numbers had been incorrect, and you'll also see corrections in the solutions below).
Solutions to sample questions

Final Exam

Other Links

An online direction field plotter. You'll need it for 1.1, and in general for plotting the direction fields for first order DEs.