Math 2233 - Differential Equations - 21014

Lecture: MWF 1:30–2:20 in MSCS 445



The main text we will follow is:

Jiří Lebl, Notes on Diffy Qs: Differential Equations for Engineers,
Freely available as PDF, HTML, or an inexpensive paperback.

It's always useful to have some other sources. The following are free online:

William F. Trench, Elementary Differential Equations (with Boundary Value Problems) (

Paul Dawkins, Paul's Online Notes - Differential Equations ( (webpages).



Jiří Lebl
Office: MSCS 505
Office hours:
MF 2:30–3:20pm, my office,
W 2:30–3:20pm, MLSC main room (5th floor of library),
and by appointment at other times.
Office phone: (405) 744-7750
Email: lebl at okstate dot edu


What's the Course About:

We study the basics of differential equations, that is, the equations that describe the world around us. They are equations not just in the unknowns, but also in their derivatives.

Prerequisites: Calculus II with grade C or better.



Grade distribution is as follows:

45% — Midterm exams, dropping the lowest midterm exam score (so 22.5% each for the other two)

40% — Final exam

15% — Edfinity online homework.

As usual, 90% and above guarantees an A, 80% and above a B, 70% a C, and 60% and above a D. Curve will be applied at the end if needed, and so those cutoff percentages could move downwards, but only if it is deemed necessary.

Grade Calculator:

Enter all grades as percentages, not as points.

Exam 1: % Exam 2: % Exam 3: %
Final: % Homework: %


Exams, Quizzes:

Exam 1: Wednesday, Feb. 14, (in class)

Exam 2: Wednesday, Mar. 13, (room PS 110 during regular class time)

Exam 3: Wednesday, Apr. 24, (room PS 110 during regular class time)

Final exam: (as per university schedule) Friday, May 10th, 2:00pm–3:50pm, room PS 110

On most questions, the "answer" that is being graded is actually your work, so points may/will be taken off for incomplete or illegible work. This includes missing or incomplete notation, don't take shortcuts! E.g., don't forget all those \(=\) signs, don't forget the \(dx\)s etc.

Nongraphing calculators are allowed on the exams. But trust me, you will not need them, and from experience in this sort of class, they just slow you down.

One sheet (letter size) of hand-written notes will be allowed on exams. Feel free to use both sides. This is only for exams.

Exams will be graded/returned through gradescope, see below.


Missed Work:

There will be reasonable accommodation for more substantial missed work if you have a valid and documented reason, and the documentation is provided in advance if available, and otherwise as soon as possible. If you have a university approved (see the syllabus attachment below) final conflict exam, you must tell me no later than two weeks before the final, so that we can figure out what to do.



Mandatory, but not taken. Students who do not regularly attend class often do much worse.


Edfinity (online homework):

Homework will be done with Edfinity, access it through canvas.



We will be using Gradescope ( for all exams and quizzes. I'll add you to the class after the first week or so, and you'll get an email on how to log in. This is where you will be able to view your graded exams/quizzes when I am done grading.



Very roughly the plan is to cover the following sections:

Chapter 0: 0.2, 0.3

Chapter 1: 1.1-1.4, 1.6-1.9

Chapter 2: 2.1-2.6

Chapter 7: 7.1-7.3

Chapter 6: 6.1-6.4


Free tutoring

The Mathematics Learning Success Center (MLSC) offers a free in-person drop-in tutoring, no appointments necessary. The MLSC is located on the 5th floor of Edmon Low Library. See our website for more information: The MLSC is a great place to meet with classmates to study. Our undergraduate tutors are trained to help you become an independent learner, so please bring your course materials and come ready to engage with the mathematics.

MLSC will offer Guided Study Groups for Differential Equations. The tutor offering these sessions is Matt Tree. They will be on Thursday at 5:00 and 6:30.


Academic integrity

You should be familiar with the University's general policies on academic integrity. You can find useful resources on this subject To boil it down: don't cheat. Don't copy work from other students or allow other students to copy your work. Don't copy work that you find in online or printed sources and present it as your own. You are welcome to collaborate with other students when completing homework and studying for quizzes and exams. You are encouraged to seek help at the MLSC when you need it. You are also free to use online resources, such as YouTube videos, that offer additional explanations and examples related to something that you are trying to learn. However, it is a violation of academic integrity to submit work that you do not understand. If I have concerns about something that you have submitted then I may ask you to meet with me to explain your reasoning.

There are online sites that provide access to complete solutions to homework exercises and allow users to upload problems and request solutions to them. There are also AI tools such as ChatGPT, Bing AI, and Bard that may provide solutions to problems posed to them. It is a violation of academic integrity to use such sites or tools in any way in connection with this class. In particular, you may not upload problems to them nor copy solutions from them.

Before quizzes and exams, you must put all unauthorized materials and devices away in a backpack or place them on a table at the front of the room. Having any unauthorized materials or devices out during a quiz or exam is a violation of academic integrity, whether or not you make any attempt to use them.


Syllabus Attachment:

See the official syllabus attachment, for some more information, like deadlines and some university-wide policies.


Interesting links:

Wolfram Alpha ( It's like Google for math.

Speaking of Google: try typing something like x^2-y^2.

But beware of using online tools for trying to solve homework problems for you. It is not a good idea. The reason for doing the homework is to learn how to do it. If you find a solution online, you will not learn anything and you will see the result of this on the exams.

If you want to type math, I recommend learning LaTeX. Best way to do that is to use Overleaf ( online.

For those more technically inclined, I recommend learning SageMath. You can use it online at CoCalc (

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