Peter Blomgren
San Diego State University
Math 254 – Introduction to Linear Algebra Spring 2019
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Video: You are looking at projections of a 4-dimensional cube, onto your 2-dimensional screen. The movement is due to the fact that we are projecting onto varying 2D planes. How to compute projections is one of the things we will cover in this class. You can see a different projection of the 4D cube in this YouTube video, and if 4D is not enough, here, you go!
If the embedded video does not work, here are direct links: [mp4, webm, mpeg]

16 Weeks of Linear Algebra...

... you won't believe what happens in week #6!
#buzzfeedNation :-P



I have given in to the Dark Side, and this course will have some Blackboard components. Mainly we will use:

  1. The Gradebook,
  2. Announcements, and
  3. Mediasite Lecture Recordings will be posted there.
    — Yes, all the lectures are being captured and posted so you can rewatch (or watch) as anytime.
  4. Doing the Right Stuff (DRS)
    — A metric based upon the activities faculty recommend as important for student success in this course. The DRS score is calculated, weighted, and posted in the grade book each week. The DRS score is not calculated into the course grade, but paying attention to the DRS column in the Blackboard grade book is encouraged. The DRS score is NOT visible to the professor!
  5. Link to the Supplemental Instruction (SI) calendar.

Class Website

The main class website resides at
There are quite a few things available there:

  1. The LECTURE SLIDES are linked from the schedule
  2. The Most Up-To-Date version of the "syllabus"
  3. The Most Up-To-Date version of the class schedule
  4. "Learning Glass" video recordings of many of the "suggested problems." (Note that new recordings may be added both here, and/or on Blackboard/Mediasite during the semester).
  5. Class "Expectations"
  6. Class "Grading Scheme"
  7. FREE is the best of all prices; so if you are less than stoked about the textbook (and/or my lectures) check out the External FREE Textbook and Video Lecture Resources


We will be using the iClicker platform for quick in-class interactions (mini-quizzes). Reference: Clicker @ SDSU (Instructional Technology Services)

These are the instructions I got from iClicker support:

  1. Download Reef app from the app store OR go to :: Student sign in :: Create an account
  2. Add the MATH 254 Introduction to Linear Algebra [Blomgren] course.
  3. Register remote and StudentID (RedID) under Reef profile
  4. One-time Account Association with iClicker Reef: Click any of the iClicker assignments or the iClicker Cloud Home​ link in Blackboard, and then sign into your Reef account. This needs to be completed only once per course​ .
    • Log into
    • go to MATH254
    • click "iClicker Cloud (SETUP)" in the sidebar
    • click "iClicker Cloud Homepage" [you may need to select an assignment(?)]
    • log into iClicker Cloud
    • (this links your iClicker account to your blackboard account)
  5. If you are using the iClicker remote, all of these steps are free and the student can ignore the banner to purchase a subscription.
  6. If you are using the reef app, the subscription rates are: $14.99 / 6 months; $23.99 / 1 year; $32.99 / 2 years; $47.00 / 4 years. (current as of 1/2/2019)

"But iClickers suck!!!" — No "interaction system" is perfect, and it is not easy to make a large (160–240 students) class truly interactive... There certainly are newer and more glamorous systems; in the past more than 80% of students entering Math 254 already had a physical iClicker; as of Spring 2018 only about 50% have a device. If you do not have a physical iClicker, the most cost effective thing to do is to either get a used iClicker, or use the reef polling app.


The Homework Server (WeBWork) is not yet up Target: Up by Friday [Second Week of Class].

Your password is: your Red ID
Your Username is your Lastname (most of the time)

Exceptions: If there are two students with the same last name, then the Usernames are LastnameF, where F is the first letter of your first name. If your Lastname on record is Hammer Head then your Username is HammerHead; if your Lastname on record is Shark-Food then your Username is SharkFood. (Note capitalization.) If you are still confused... ask.


"Piazza is a free online gathering place where students can ask, answer, and explore 24/7, under the guidance of their instructors. Students as well as instructors can answer questions, fueling a healthy, collaborative discussion."


Contact Information


Peter Blomgren
blomgren DOT peter AT gmail DOT com
Class hours: TuTh 9:30a – 10:45a, HT-140
Office hours: TuTh 11:00a – 11:50a, TuTh 2:00p – 2:50pm (GMCS-587), and by appointment.

Supplemental Instruction (SI) Hours

Supplemental Instruction (SI) study sessions are offered for this course. SI Sessions occur every day, 7 times each week, throughout the entire semester. Supplemental Instruction Sessions are peer-led, voluntary, and faculty do not know who attends and who does not participate. SI is for everyone, and open to all students enrolled in this class; not just those students who are struggling.

The sessions provide group study opportunities to assist students in traditionally difficult courses. To get the most out of SI, attend early and often during the semester. Sessions are facilitated by an SI Leader who has already received an A or B+ in the class, and has been trained to lead group sessions where students can improve their understanding of course material, review and discuss important concepts, develop study strategies and prepare for exams. Students who begin attending SI sessions early in the semester typically earn higher final course and exam grades than students who do not participate in SI. Please bring your lecture notes, books, and questions with you to the SI sessions.

Check out the [SI Calendar] for times and locations.

"Meet" your MATH 254 SI Leaders:

What is SI?:

TA Office Hours

Sidney, GMCS-528, (details TBA)

Optional Book, and Other Resources

Course Outline (Topics)

Linear Equations, Vectors, Linear Transformations, Subspaces of ℜn and Their Dimensions, Orthogonality (and Least Squares), Determinants, Eigenvalues and Eigenvectors, (Symmetric Matrices and Quadratic Forms.)

Class website

In particular, the lecture slides!

Suggested Text and Reading Materials:

Introduction to Linear Algebra (fifth edition), Gilbert Strang, Wellesley-Cambridge Press / Society for Industrial and Applied Mathematics, 2016, ISBN-10 0-980-23277-5, ISBN-13 978-0-980-23277-6

Errata: None known.

The Textbook Costs 250+ Tacos!

[ Fall 2018 – current ] The extended notes (lecture + supplemental material) now constitute the "book," and can be downloaded from this site for $0. (With a complete money-back-guarantee) Gilbert Strang's book (see below) is now recommended (but explicitly "optional") reading.

[ Spring 2017 ] I have adopted a new text book [Gilbert Strang's Introduction to Linear Algebra, Fifth Edition (2016)], which not only is supposed to be better, but it is also less expensive than the old one. ($86.25* vs. $200.00+)

Surveys have shown that 66% of students skip buying at least one textbook due to it being too expensive. Of those students 94% feel that they suffer(ed) academically from this choice.

I has also included links to some the External FREE Textbook and Video Lecture Resources section on the website. Notably, you can watch Gil Strang's lectures (recorded in 1999) for free!

Campus Resources and Information

Math Learning Center

The SDSU Math Center is in the Love Library, Room LL-328. The goal of this center is to provide a central location for students from all lower division mathematics and statistics courses to find free, on-demand tutoring.

The MLC primarily targets Math 141, 150, 151, and 252.

Students with Disabilities:

If you are a student with a disability and believe you will need accommodations for this class, it is your responsibility to contact Student Disability Services at (619)594-6473. To avoid any delay, please contact Student Disability Services as soon as possible. Please note that accommodations are not retroactive, and cannot be provided until an accommodation letter from Student Disability Services is received by the Professor.


As of Spring 2016, Crashing has been replaced by the Waitlist. Note that professors have VERY LITTLE power over the waitlist, most of the action is "automatic."

General Course Information

Catalog description

Matrix algebra, Gaussian elimination, determinants, vector spaces, linear transformations, orthogonality, eigenvalues, and eigenvectors.

  • 1. Math 151 (Calculus II) — Grade C or better required.


Mandatory problems collected online using WeBWorK. Approximately one assignment per chapter (8-10 assignments). [details TBA]

Recommended problems (not collected) will be also be assigned.

The WeBWork problems are somewhat simplisitic — solving only these problems WILL NOT prepare you for the exams! Do attack the "suggested problems" – they are suggested for a reason! (And do check out the learning glass video solutions)

Syllabus / Schedule Modifications

I reserve the right to modify the syllabus / schedule as needed to work around unforseen events, etc. Announcements may be sent out via Blackboard; and PLEASE make it a point to regularly check the calendar.

Copyright © 2019 Peter Blomgren.