arminstraub.com

Fall 2024: Differential Equations I (Math 238)

Overview

Instructor Dr. Armin Straub
MSPB 313
straub@southalabama.edu
(251) 460-7262 (please use e-mail whenever possible)
Office hours MWF 10:00-11:00am, 12:15-1:15pm, or by appointment
Lecture MWF, 9:05-9:55am, in MSPB 235
Midterm exams The tentative dates for our two midterm exams are:
Wednesday, October 2
Wednesday, November 13
Final exam Wednesday, December 11 — 8:00-10:00am
Online grades Homework Scores
Exams: USAonline (Canvas)
Syllabus syllabus.pdf

Lecture sketches and homework

To help you study for this class, I am posting lecture sketches. These are not a substitute for your personal lecture notes or coming to class (for instance, lots of details and motivation are not included in the sketches). I hope that they are useful to you for revisiting the material and for preparing for exams.

Date Sketch Homework
08/21 lecture01.pdf Homework Set 1: Problems 1-3 (due 9/4)
08/23 lecture02.pdf Homework Set 1: Problems 4-5 (due 9/4)
08/26 lecture03.pdf Homework Set 1: Problem 6 (due 9/4)
08/28 lecture04.pdf Homework Set 2: Problems 1-2 (due 9/11)
08/30 lecture05.pdf Homework Set 2: Problems 3-4 (due 9/11)
09/04 lecture06.pdf Homework Set 2: Problem 5 (due 9/11)
09/06 lecture07.pdf Homework Set 3: Problem 1 (due 9/18)
09/09 lecture08.pdf Homework Set 3: Problems 2-3 (due 9/18)
09/11 lecture09.pdf Homework Set 3: Problems 4-5 (due 9/18)
09/13 lecture10.pdf Homework Set 4: Problems 1-2 (due 9/25)
09/16 lecture11.pdf Homework Set 4: Problems 3-4 (due 9/25)
09/18 lecture12.pdf Homework Set 4: Problem 5 (due 9/25)
09/20 lecture13.pdf Homework Set 5: Problem 1 (due 10/2)
09/23 lecture14.pdf Homework Set 5: Problem 2 (due 10/2)
09/25 lecture15.pdf Homework Set 5: Problems 3-5 (due 10/2)
09/27 lecture16.pdf exam practice problems (as well as solutions) are posted below
09/30 review get ready for the midterm exam on 10/2 (Wednesday)
10/04 lecture17.pdf Homework Set 6: Problems 1-3 (due 10/18)
10/07 lecture18.pdf Homework Set 6: Problems 4-5 (due 10/18)
10/09 lecture19.pdf Homework Set 6: Problem 6 (due 10/18)
10/14 lecture20.pdf Homework Set 7: Problem 1 (due 10/25)
10/16 lecture21.pdf Homework Set 7: Problems 2-4 (due 10/25)
10/18 lecture22.pdf Homework Set 7: Problem 5 (due 10/25)
10/21 lecture23.pdf Homework Set 8: Problems 1-2 (due 11/1)
10/23 lecture24.pdf Homework Set 8: Problems 3-4 (due 11/1)
10/25 lecture25.pdf Homework Set 8: Problems 5-6 (due 11/1)
10/28 lecture26.pdf Homework Set 9: Problem 1 (due 11/11)
10/30 lecture27.pdf Homework Set 9: Problems 2-4 (due 11/11)
11/01 lecture28.pdf Homework Set 9: Problem 5 (due 11/11)
11/04 lecture29.pdf Homework Set 9: Problem 6 (due 11/11)
11/06 lecture30.pdf finish all homework
11/08 lecture31.pdf exam practice problems (as well as solutions) are posted below
11/11 review get ready for the midterm exam on 11/13 (Wednesday)
11/15 lecture32.pdf Homework Set 10: Problems 1-2 (due 11/27)
11/18 lecture33.pdf Homework Set 10: Problems 3-4 (due 11/27)
11/20 lecture34.pdf Homework Set 10: Problem 5 (due 11/27)
lectures-all.pdf (all lecture sketches in one big file)
Overview of all homework problems

About the homework

  • Homework problems are posted for each unit. Homework is submitted online, and you have an unlimited number of attempts. Only the best score is used for your grade.

    Most problems have a random component (which allows you to continue practicing throughout the semester without putting your scores at risk).

  • Aim to complete the problems well before the posted due date.

    A 15% penalty applies if homework is submitted late.

  • Collect a bonus point for each mathematical typo you find in the lecture notes (that is not yet fixed online), or by reporting mistakes in the homework system. Each bonus point is worth 1% towards a midterm exam.

    The homework system is written by myself in the hope that you find it beneficial. Please help make it as useful as possible by letting me know about any issues!

Online calculator

At certain points, you probably want to verify your answers to the homework problems before submitting them (so that you don't need to start over on a lengthy problem with lots of algebra). You can, of course, use any fancy calculator or various websites for that purpose. One particularly nice resource is WolframAlpha. For instance, to solve Example 38 in Lecture 8, you can just enter the following into WolframAlpha:

y' = (2x-3y)^2+2/3, y(1)=1/3

Exams and practice material

The following material will help you prepare for the exams.