Mathematics 285

Spring 2020 University of Nevada Reno

285 DIFFEREN EQUATIONS (3) 3 credits

Instructor   Course Section                    Time                Room
Eric Olson   1005 Math 285 DIFFEREN EQUATIONS  MW 4-5:15am        OB102
We are now meeting at the same times through Zoom on the UNR WebCampus. Don't forget to continue checking this page as well.

Course Information

Eric Olson
ejolson at unr edu
Please correspond using WebCampus if possible, if not then put the number 285 in the subject line.
Tuesday at 1pm through Zoom and by appointment. For the Zoom meeting number please check the schedule on WebCampus.

Required Texts:
Dennis Zill, A First Course in Differential Equations with Modeling Applications, 10th or 11th Edition, Brooks Cole, 2012 or 2017.

Student Learning Outcomes

We will cover selected sections in Chapters 1 through 5, 7 and 8 of the textbook. Upon completing this course, a student shall be able to

Lecture Notes

Here are lecture notes from the distance learning classes to help people catch up who may have experienced technical difficulties during the lecture. Please note that attendence is being taken at the online lectures. This is to ensure everyone is included and continues to receive as much support as possible.

If you miss a lecture, it is just as important as before to let me know the reason and to catch up the missed material. In addition to the usual university approved reasons for missing a class, it may happen that the technology doesn't work--either at your end or at mine (or both). In such cases, don't panic, technical difficulties will be considered a valid excuse for missing class. Even so, it is important to resolve such difficulties quickly to avoid future problems.


[07-May-2020] Thank You

[11-May-2020] Final Exam

The final exam will be held on Monday, May 11 from 2:30 to 4:30pm on Zoom please see the meeting link in WebCampus.

[29-Apr-2020] Exam 3

Exam 3 will be given April 29 and cover Laplace transforms. There is now a sample exam available on WebAssign.

[27-Apr-2020] Eigenvectors and Eigenvalues

In class we solved the eigenvalue eigenvector problem using a computer algebra system called Mathematica and also with Matlab. For your reference, here are screen captures of that work.

[22-Apr-2020] Delta Function Video

I found a recitation about step and delta functions which is part of the MIT OpenCourseWare for 18.03SC Differential Equations Fall 2011. Hopefully this will help to build additional intuition about what we discussed today in class.

[08-Apr-2020] Laplace Transform Table

I have scanned the table of Laplace transforms because I had difficulty reading the one in the online textbook.

[06-Apr-2020] Quiz 2

Quiz 2 has been postponed until April 6 in order to give people enough time to adapt to the technology used for distance learning. Sample exams and a description of how the test will be administered online are forthcoming.

[24-Mar-2020] Lecture Notes

I have posted lecture notes to summarize what we covered on Monday. While there were some obvious technical difficulties during our first Zoom lecture, I have now connected my computer directly to the cable modem and will be making other changes as needed so things run smoothly. Please check the disucssion forums on WebCampus for more details.

[23-Mar-2020] Switch to Online Learning

As described at the UNR webpage on the novel coronavirus The recommended software for distance learning will be provided by Zoom Video Communications and accessible by means of a link on our course page at UNR WebCampus. Please check the canvas page for the Meeting ID and Join URL under the Zoom tab.

We will video conference the scheduled class time at 4:00pm on Monday and Wednesday. You may need to register for a Zoom account before then and install the conferencing software on a suitable computer or mobile phone. Please let me know if you have difficulty installing the software or finding the Join URL ahead of time so we can fix the technology before the first class meeting. Given the unique nature of these arrangements, video attendance will be mandatory.

[19-Feb-2020] Quiz 1

In class on Wednesday February 19 we will have our first quiz covering Chapter 2.1 through 2.5. Note that Chapter 2.6 is omitted. I have created two sample tests to help you study.

[14-Feb-2020] Sample Quiz 1 Version 2

Here is another sample sample exam to help you study for Quiz 1. I will be posting answer keys for both sample tests over the weekend. Please check back so you can see my work before taking the exam in class on Wednesday.

[08-Feb-2020] Sample Quiz 1 Version 1

I have created a sample exam to help you study for Quiz 1. Please look it over. If you have questions please ask in class on either Monday February 10 or Wednesday February 12.

[22-Jan-2020] First Lecture

The first lecture introduced the idea of a differential equation and proceed to solve the linear differential equations of the form

y' + P(x) y = f(x)

as covered in Section 2.3 of the textbook.


All homework is to be completed on Webassign. You are responsible for keeping track of all assignments and their due dates. Solving homework problems will help you to understand the key concept and to master the skills you will need to succeed in this course. You should try to work on the problems assigned for a section as soon as the material is covered. You may discuss problems with other students, but all submitted work should be your own. Go to and use the code

unr 6887 9573

You will be asked to set up a Webassign account if you do not already have one. Please use exactly the same name and email you use to register for courses at UNR.


     Quiz 1                    20 points each
     Quiz 2                    40
     Exam 1                    60 points
     Final Exam               100 points
     Homework Assignments      40 points
                              260 points total

Exams and quizzes will be interpreted according to the following
grading scale:

    Grade        Minimum Percentage
      A                 90 %
      B                 80 %
      C                 70 %
      D                 60 %

The instructor reserves the right to give +/- grades and higher grades
than shown on the scale if he believes they are warranted.

Final Exam

The final exam will be held on Monday, May 11 from 2:30 to 4:30pm on Zoom please see the meeting link in WebCampus.

Equal Opportunity Statement

The Mathematics Department is committed to equal opportunity in education for all students, including those with documented physical disabilities or documented learning disabilities. University policy states that it is the responsibility of students with documented disabilities to contact instructors during the first week of each semester to discuss appropriate accommodations to ensure equity in grading, classroom experiences and outside assignments.

Academic Conduct

Bring your student identification to all exams. Work independently on all exams and quizzes. Behaviors inappropriate to test taking may disturb other students and will be considered cheating. Don't talk or pass notes with other students during an exam. Don't read notes or books while taking exams given in the classroom. Homework may be discussed freely. If you are unclear as to what constitutes cheating, please consult with me.

The following is new university policy: Surreptitious or covert video-taping of class or unauthorized audio recording of class is prohibited by law and by Board of Regents policy. This class may be videotaped or audio recorded only with the written permission of the instructor. In order to accommodate students with disabilities, some students may be given permission to record class lectures and discussions. Therefore, students should understand that their comments during class may be recorded.

Last Updated: Wed Jan 22 15:37:20 PST 2020