Matrix Algebra

Spring 2026


Instructor: Matt Kerr
Office: Cupples I, Room 114
e-mail: matkerr [at] wustl.edu
Office Hours: Monday 2-3 and Friday 2-3
Class Schedule:

[Please note: Math 3300 has 4 sections this semester. This webpage only pertains to section 3.]

Lectures are on Monday, Wednesday, and Friday from 1:00-1:50 in Rebstock 215, beginning Monday Jan. 12 and ending with a final exam review class on Friday Apr. 24. Holidays are Jan. 19 and Mar. 9-13.

Midterm Exam 1: Friday, Feb. 20 (in class), on Chapters 1--3
Midterm Exam 2: Friday, Apr. 10 (in class), on Chapters 4--5
Final Exam: 8:30-10:30 PM, May 4, room TBA

Regarding missed exams, see the Grading Policy section below. Calculators aren't allowed, but the exams will not be computationally heavy.

Copies of old exams are maintained at this link. Exam solutions will appear on Canvas.
Textbook:

David Lay, Steven Lay, and Judi McDonald, Linear Algebra and its Applications (6th Ed.), Pearson, 2021. [WU Bookstore listing]

We will cover Chapters 1-6 and the beginning of 7. The cheapest option is renting an electronic copy for 6 months.

The original author of the previous editions (David Lay) has some friendly advice on learning from his book.
Course Goals:

This is an introductory course in linear/matrix algebra. You can expect a mild amount of abstraction, but the emphasis is on topics which are useful in science, engineering, and business. My goal is for each of you to come away in 15 weeks with a good understanding of:

  • Linear systems, row-reduction, and matrix equations
  • Linear transformations, invertibility, rank+nullity
  • Determinants
  • Vector spaces, basis and dimension
  • Eigenvectors and eigenvalues, diagonalization
  • Inner products, orthogonality, Gram-Schmidt
  • The spectral theorem and quadratic forms

    • Assignments:

    These will comprise:

  • A weekly Webwork due on Friday (at 8 PM) --- about 5-10 computational problems, covering up through Wednesday's lecture. Webwork must be accessed through Canvas. The webwork due on Friday will become available on Tuesday morning.

  • A weekly written homework due by 5 PM on Tuesday (except for HW 1, due Wednesday, and the last two HWs, due Thursday) --- around 10 problems, more theoretical in nature and covering the previous week's lectures. (The problems are listed below the next table.) You will submit these as a PDF upload through Gradescope (or through Canvas, if this link doesn't work). Solutions will appear on Canvas.

    • I encourage you to visit my office hours (chosen with this schedule in mind) to discuss both kinds of problem sets, and to form study groups to discuss the more difficult problems (though solutions must be written up independently). Regarding late homework, cf. the Grading Policy below.

    Assignment table (Note: "Week of" date refers to Monday.)

    Week of ... Homework (due Tues) Webwork (due Fri)
    Jan. 12 (Week 1) no WW no HW
    Jan. 19 (Week 2) HW 1 (due Wed.) WW 1
    Jan. 26 (Week 3) HW 2 WW 2
    Feb. 2 (Week 4) HW 3 WW 3
    Feb. 9 (Week 5) HW 4 WW 4
    Feb. 16 (Week 6) HW 5 no WW
    Feb. 23 (Week 7) no HW WW 5
    Mar. 2 (Week 8) HW 6 WW 6
    Mar. 9 SPRING BREAK
    Mar. 16 (Week 9) HW 7 WW 7
    Mar. 23 (Week 10) HW 8 WW 8
    Mar. 30 (Week 11) HW 9 WW 9
    Apr. 6 (Week 12) HW 10 no WW
    Apr. 13 (Week 13) HW 11 (due Thu.) WW 10
    Apr. 20 (Week 14) HW 12 (due Thu.) no WW

    Assignment list: (WARNING: based on GLOBAL 6th edition -- problems may differ from US version. I will continue to post PDFs of the pages containing the correct problems under Files on Canvas.)

    HW #1 (due Jan. 21): §1.1: #28-34 even (as one problem), 37, 43, 44; §1.2: #4, 12, 20, 42; §1.3: #14, 18, 22, 40
    HW #2 (due Jan. 27): §1.4: #10, 16, 18, 24-34 even (as one problem); §1.5: #6, 12, 20, 42; §1.6: #8, 14
    HW #3 (due Feb. 3): §1.7: #32, 42, 44; §1.8: #18, 38, 42; §1.9: #8, 18, 34, 38
    HW #4 (due Feb. 10): §2.1: #12, 30, 32, 34; §2.2: #26, 34, 42; §2.3: #6, 22; §2.4: #6; §2.5: #2, 8
    HW #5 (due Feb. 17): §2.3: #28, 46; §2.6: #4; §3.1: #10, 18; §3.2: #10, 26, 36, 42; §3.3: #32
    HW #6 (due Mar. 3): §4.1: #6, 16, 40; §4.2: #6, 10, 22, 44; §4.3: #8, 14; §4.4: #10, 12, 14, 36; §4.5: #4, 12, 28
    HW #7 (due Mar. 17): §4.5: #38, two supplementary problems (see Gradescope); §4.6: #8; §4.8: #14, 32; §5.9: #4, 14, 28
    HW #8 (due Mar. 24): §5.1: #16, 44; §5.2: #8, 14, 18; §5.3: #6, 14, 16, 32
    HW #9 (due Mar. 31): §5.4: #8, 10, 28; §5.5: #4, 8, 14; §5.6: #2, 4
    HW #10 (due Apr. 7): §5.7: #4; §6.1: #14, 34, 36; §6.2: #12, 14, 16, 42
    HW #11 (due Apr. 16): §6.3: #12, 16, 32; §6.4: #6, 14, 24; §6.5: #2, 6, 10, 16
    HW #12 (due Apr. 23): §6.6: #2, 12; §6.7: #32; §7.1: #10, 20, 32; §7.2: #8, 10, 12, 20

    Lecture Notes:

    In the calendar below I will post my notes for each lecture, after the class takes place. Click on the "Lec X" link (once it is active) for the notes. The sections covered in the lecture are also displayed in the table (though these sections may not be covered in full).

    The lecture notes are intended to help you prepare for exams, fill in bits you may have missed in lecture, or even avoid taking notes altogether. They are not intended, however, as a substitute for class attendance and reading the book.

    Week Monday Wednesday Friday
    1 [Lec 1] 1.1 [Lec 2] 1.2 [Lec 3] 1.3
    2 MLK Day [Lec 4] 1.4,6 [Lec 5] 1.5
    3 [Lec 6] 1.7 [Lec 7] 1.8 [Lec 8] 1.9
    4 [Lec 9] 2.1 [Lec 10] 2.2,3 [Lec 11] 2.3,4,5
    5 2.6,3.1 3.2 3.3
    6 4.1 4.2 [Exam 1]
    7 4.3 4.4 4.5
    8 4.5 4.6 4.8,5.9
    --- SPRING --- BREAK
    9 5.1,2 5.2,3 5.3,4
    10 5.4 5.5 5.6
    11 5.7 6.1 6.2
    12 6.3,4 6.4,5,6 [Exam 2]
    13 6.5,6 6.7 7.1
    14 7.2 7.4 Review

    Grading Policy:

    Homework is worth 20%, Webwork 10%, Midterm Exam 1 and Midterm Exam 2 are worth 15% each, and the Final Exam is worth 40%. I will drop your lowest 2 homework and lowest 2 webwork scores.

    Curving and grade scale: In the event that the average score on any exam is less than 75%, all exam scores will be adjusted upward by adding a constant to everyone's score (so that the average is 75%). No adjustment is made if the average is above 75%. The grade scale is as follows:

    A+ A A- B+ B B- C+ C C- D F
    TBA 90+ [85,90) [80,85) [75,80) [70,75) [65,70) [60,65) [55,60) [50,55) [0,50)

    The Pass/Fail policy is that you must get at least a C- to earn a "Pass".

    Grades will be kept track of on Canvas, though Webwork will only be entered there as block scores at the end of the course. (In the meantime, you will be able to keep track of your scores on individual WW sets on the website where you hand them in.)

    If you have to miss a midterm exam for a legitimate reason, you will be given an excused absence for that exam, and your grade will be calculated from the homework and other taken exams. Of course verified illness and serious family emergency are legitimate reasons. Regarding other conflicts, e-mail me as soon as you know about them.

    Verified illness and serious family emergency are in general the only acceptable reasons for missing the final exam. In this event, you will receive an Incomplete and will have to make up the exam later to resolve this.

    In general, credit will be given for late Webwork/Homework only in the event of illness or emergency.

    This link takes you to the standard university policies on academic integrity.
    Academic Support:

    In addition to my office hours, drop-in mentoring will be available for Math 3300 beginning the third week of the semester. I'll post more information here as it becomes available.