January-April 2017: Math 215/255: Differential Equations Common Page

Instructors: Daniel Coombs, Dimitrios Roxanas and Mona Rahmani.
Math department tutoring centre is located in LSK 301/302.

Links to section web pages:
  • Math 215 Section 201 (Roxanas, 10am in LSK 200)
  • Math 215 Section 202 (Coombs, 9am in BUCH A201)
  • Math 255 Section 201 (Rahmani, 10am in LSK 201)

  • Text: Our main reference will be the online textbook Diffy Qs by Lebl. You can download the book (for free) or order a copy (for cheap) to be sent to you from this page: http://www.jirka.org/diffyqs.
  • Clickers will be used in some sections of this course. Please confirm with your section instructor about whether you need to get a clicker (available from the bookstore).
  • Matlab/Octave. You will need one of these tools for some of the homework in this class. See below for instructions about how to get one of these programs for your personal computer. You can also/alternatively use the Math department computer labs.
  • Additional free online notes are available at the following sites:
    Paul's online notes (highly recommended)
    http://www.springerlink.com/content/p78848/?MUD=MP (for the last link you will need to be accessing from UBC, either directly or via VPN: http://www.it.ubc.ca/service-catalogue/internet-and-telephone/network-management/myvpn)
    You can also consult physical textbooks. Some favourites are Boyce and DiPrima (any recent edition) and Edwards and Penney. Boyce and DiPrima has often been used at UBC.
  • Gustafson's notes on nonlinear systems

    Important Dates:

  • Final exam: April 21, 2017 at 7pm. Locations: Math 215 (both sections) will write the exam in WOOD 2. Math 255 will write in WOOD 6.

    List of Topics

  • List of topics for Final Exam: [PDF]
  • Table of Laplace Transforms. This table will be available for you to refer to on the final exam.

    Final Exam Resources

  • Previous math 215 exams. Note that different topics receive more or less emphasis in different years.
  • UBC Math Exam Resources wiki.
  • UBC Math club.Will sell you some previous exams with solutions. Carefully note their opening hours.
  • Additional review problems with solutions.


  • The breakdown of marks between course elements will be as follows: Final exam 50%, Homework 15%, Webwork 10%, Midterms 10% each, in-class quizzes, questions and/or clickers 5%.
  • Missing a midterm or quiz normally results in a mark of 0. Exceptions may be granted in two cases: prior consent of the instructor or a medical emergency. In the latter case, the instructor must be notified within 48 hours of the missed test, and presented with a doctor's note immediately upon the student's return to UBC. No make-up midterms will be given.
  • Term marks may be scaled up or down on a classwide basis, depending on performance on the final exam. This is to ensure fairness across both sections of the course.
  • You must submit only your own work. Although you are welcome to study together and discuss the homework with other students, the work you submit (electronically or on paper) must be your own. UBC policies on cheating and plagiarism are extremely strict. If in doubt, enquire before submitting.

    Written Homework

  • Some homework questions will require use of Matlab/Octave to solve problems numerically. See below for instructions on obtaining Matlab/Octave and for TA help hours.
  • Homework 1 [PDF] and a needed Matlab file, dirfield.m. Due in class, Jan 20.
  • Solutions [PDF]
  • Homework 2 [PDF] and Matlab files, EulerHW2.m ImprEulerHW2.m. Due in class, Feb 3rd.
  • Solutions [PDF]
  • Homework 3 [PDF] and Matlab file, vecfield_systems.m . Part 2 of this homework (problems 7-13) due in class, Monday Feb 27th EXTENDED TO Friday March 3rd.
  • Solutions to both parts [PDF]
  • Homework 4 [PDF] and two potentially helpful Matlab files: NLVecField.m two_salt_tank_mixing_w_forcing.m Due in class, March 17th.
  • Solutions [PDF]
  • Homework 5 [PDF] Due in class Friday, March 31st.
  • Solutions [PDF]
  • Homework 6 [PDF] will not be collected, but you should do the questions before the final exam.
  • Solutions [PDF]


    Webwork will be due before 10pm on Mondays, starting from Monday January 16th. Please login to the course webwork page. The problems will be available 1 week in advance.

    Midterms and Quizzes

  • List of topics for Midterm 1: [PDF]
  • Practice questions relevant to midterm one with some solutions. Note that not all topics are covered by these questions.
  • Solutions to Midterm 1: Version 1 [PDF] (minor corrections posted Feb 22) and Version 2 [PDF]
  • List of topics for Midterm 2: [PDF]
  • Practice questions relevant to midterm two with some solutions. Note that not all topics are covered by these questions. Some more questions still to be added, please check back later.
  • Solutions to Midterm 2: [PDF].

    Computer homework information

    Getting the needed software

  • Computer homework information will be given in class as needed.
  • Here are three options for obtaining software needed for the homework.
  • (1) Matlab is available from UBC IT services for UBC students to install on their own computers. You do not need any additional toolboxes for this class, but that is up to you.
  • (2) You can install Octave. Octave is a free program that is quite similar to Matlab so that most programs are easily portable from one to the other. Installation of Octave on Windows and Linux is fairly simple (in fact if you have a recent Linux distribution, Octave might already be installed). However on Mac computers, installation has been reported to be a bit trickier. We will not help you install software on your personal computer.
  • (3) You can use the Mathematics undergrad computer labs, located in LSK 121 and LSK 310. The labs are open from 8am-6pm Monday to Friday. LSK 310 is also where the TA help will be available (either on a lab computer, or take your laptop). To use the lab computers you will need to login using a user account. Follow the instructions that will be sent to you by email (and/or ask the TAs during lab hours for assistance).

    Lab TA hours:

    For help with Matlab, TAs will be available in LSK 310 at the following times (subject to change through the semester, please check back for updated hours):
  • Monday: 2pm-4pm.
  • Tuesday: 10am-11am and 4pm-6pm.
  • Wednesday: 4pm-6pm.
  • Thursday: 12pm-1pm, 3pm-4pm and 5pm-6pm.

    Matlab and Octave resources

  • UBC Math Matlab/Octave resources page.
  • Matlab is used by lots of people worldwide. The Mathworks help site is a good place to look for help, but often you will also find an answer by directly using Google or another search engine.
  • Useful notes on Matlab for novices [PDF].
    Daniel Coombs / Department of Mathematics / University of British Columbia