MAT 2580 Linear Algebra

Professor Poirier | D712 | Spring 2026

Week 2 checklist

Tuesday, February 3 to Monday, February 9

Lessons

  • 1.2 Systems of Equations, Algebraic Procedures (continued)
  • 2.1 Matrix Addition and Scalar Multiplication
  • 2.2 Matrix Multiplication
  • 2.3 The Transpose
  • 2.4 The Identity Matrix and Matrix Inverses (if time)
  • 2.5 Finding the Inverse of a Matrix (if time)

WeBWorK

Due Monday, February 9 11:59pm

(Scroll down on the landing page to see the sets that are still open for reduced scoring until Tuesday night)

  • Gaussian Elimination
  • Matrix Operations
  • The Inverse of a Matrix (postponed until Monday, February 16)

OpenLab

Due Monday, February 9 11:59pm

  • Time machine
    • Instructions: Respond to one comment on this post or this post or this post on previous semesters’ OpenLab sites. Find one comment that you found particularly helpful. Begin your reply with “Hi, [commenter’s name]. I am a student in MAT 2580 now. I found your advice helpful because [then explain in a sentence or two why their advice resonated with you].”
    • Since this is a comment on a different OpenLab site, your comment will have to be approved by the site administrator before it appears.
  • Applications of linear algebra (comment; instructions)

Reminders

  • Next Thursday, February 12 is a holiday and no classes are scheduled for the following Tuesday, February 17. So we see each other on Tuesday, February 10 and then not again until Thursday, February 19 (academic calendar)
  • Office hours are held on Tuesdays and Thursdays from 12pm to 1pm. Usually, they will be held in my office N707, but if I’m not there, check N618.

Week 3 checklist

Tuesday, February 10 to Monday, February 16

Lessons

  • 2.4 The Identity Matrix and Matrix Inverses
  • 2.5 Finding the Inverse of a Matrix

WeBWorK

Due Monday, February 23 11:59pm

  • The Inverse of a Matrix
  • Characterizations of Invertible Matrices
    • While these sets are not due until February 23, try to complete at least the first 5 problems on each set by February 16

OpenLab

Due Monday, February 16 11:59pm

  • [Post] Choose one of the first 5 problems of the WebWorK set The Inverse of a Matrix and post your full solution on the OpenLab
    • Title: Finding an inverse
    • Category: Finding an inverse
  • [Comment] Black History Month profile (instructions)

Other

  • This Thursday, February 12 is a holiday and no classes are scheduled for the following Tuesday, February 17. So we see each other on Tuesday, February 10 and then not again until Thursday, February 19 (academic calendar)
  • Office hours have been rebranded and are now called WeBWorK Parties. They are held on Tuesdays and Thursdays from 12pm to 1pm. Stop by N618 (or my office N707 if I’m not in N618).

OpenLab assignment: Black history month profile!

Comment due Monday, February 16

Animated gif that looks like writing on a chalkboard that says "Black history is happening now"

It’s Black history month! For this assignment, you will write a short profile or biography of a Black mathematician or math educator (or someone else in the Black-in-math community). You will submit your profile as a comment on this post. You have lots of choices for where to find this information and you can use whatever resources you like. Here are two suggestions:

Suggestion 1: 

https://twitter.com/BlackInMath/status/1323061374747103236?s=20

A few years ago, the @BlackInMath account on Twitter hosted #BlackInMathWeek to celebrate living Black mathematicians. If you have an account, you can scroll back to see the old posts where Black mathematicians introduced themselves.

Suggestion 2: 

The awesome website Mathematically Gifted & Black has honored a new person every day of Black History Month in recent years. You can check out honorees on the Circle of Excellence tab at the top of their page. (You can also check out their Instagram page.)

Instructions

Pick one Black mathematician or math educator to learn about. Aside from their MG&B profile or their Twitter introduction, what else can you learn about them? (How has their life changed since their Twitter introduction or their MG&B profile?) Write a short biography (5 or 6 sentences….or more!) of this person. Include their name and where they are on their math journey (are they a graduate student? a professor? a teacher? where? do they do research in math? are they involved in the Black-in-Math community in some other way?). Include a photo of them if you like. Include the field of math that they study and anything else you can tell us about them! What makes this person so awesome and interesting to you? What questions do you have for them? Include links to the pages where you found information about them.

Submit your profile as a comment on this post below for participation credit

Fun fact

Most of you might be too young to know who the rapper MC Hammer is, but he was a childhood hero of mine. He’s an activist too and in modern times he’s used his Twitter platform to promote different #BlackInSTEM initiatives, including #BlackInMath.

https://twitter.com/MCHammer/status/1325938040305410048?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1325938040305410048%7Ctwgr%5E%7Ctwcon%5Es1_c10&ref_url=https%3A%2F%2Fopenlab.citytech.cuny.edu%2Fpoiriermat1575fall2020%2F2020%2F11%2F08%2Fassignment-blackinmathweek-on-twitter%2F

During Black in math week, MC Hammer retweeted and followed my friend Marissa AND IT WAS SO EXCITING!!! (PS, Someone should totally profile Marissa for this assignment because she is a BOSS! BTW she’s no longer a postdoc at Georgia Tech; she’s now a professor at University of Wisconsin–Madison.)

Fahim Intrduction

Hello, my full name is Fahim Ahmed. It’s nice to meet everyone. During this semester i hope to get to know everyone. I would like to start by talking about my current major, which is computer science. I plan on doing my associate’s degree, although it may not be the major I decided on. I learned a lot and met lots of interesting people. As for my hobbies, I enjoy boxing, working out, and sports. I may not be the best at it, but I enjoy pushing myself. Unfortunately, I have epilepsy, so it makes a lot of things difficult, and I always have to be careful. At the moment, it is controlled and at bay with medication, which I have to take at a strict time. I hope to have a wonderful semester.

– Fahim Ahmed

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