Math 2121 (Fall 2026)
Overview
Welcome to the homepage for Math 2121: Linear Algebra!
- Send questions for an instructor to emarberg@ust.hk or maymin@ust.hk.
- Send questions about grades to your TA.
Check out the syllabus here.
Lecture notes
Our lectures this semester will be online at the following times:
- L1: Tuesdays & Thursdays, 16:30 - 17:50
- L2: Tuesdays & Thursdays, 15:00 - 16:20
- L3: Mondays, 13:30 - 14:50, & Fridays, 9:00 - 10:20
For lecture locations consult the university registry.
New lecture notes will be posted each Friday. Try to read these before each class.
Week 1:
Week 2:
- Lecture 3: Vectors in Euclidean space
- Lecture 4: Matrix-vector products, linear independence
Week 3:
- Lecture 5: More linear independence, linear transformations
- Lecture 6: One-to-one and onto functions
Week 4:
- Lecture 7: Matrix operations, matrix multiplication
- Lecture 8: Invertible functions and invertible matrices
Week 5:
Week 6:
Other resources
The following is our primary textbook:
- Linear Algebra and its Applications, 6th edition, by D. Lay, S. Lay, and J. McDonald
Some other online resources:
Grades
Grades will be computed as follows:
- 5%: online homework assignments
- 5%: offline homework assignments
- 30%: midterm examination
- 60%: final examination
Homework
There are two components to the homework in this course: online and offline.
We will have weekly online homework assignments. Here are the relevant logistics:
- Online homework will be submitted using WebWork.
- More information about deadlines will be announced later.
There is also a weekly offline component to the homework. Here are the relevant logistics:
- A list of practice problems will be posted each week with the lecture notes.
- You must solve some of these probems (see instructions) and submit your answers by hardcopy.
- More information about deadlines (and how to submit) will be announced later.
For both parts of the homework, no deadline extensions will be granted and no late submissions will be accepted
but we will omit your lowest online score and lowest offline score from final grade computations.
This means you can skip any one week of homework with no penalty.
Midterm
We will have a 2 hour, out-of-class midterm. The date and time are TBD.
The midterm will be closed book, closed notes,
with no calculators or other electronic devices allowed.
Final
We will have a cumulative 3-hour final exam at the end of the semester.
This exam will also be closed book, closed notes,
with no calculators or other electronic devices allowed.
Schedule
The following is a tentative course outline, with reading assignments from the textbook.
- Week 1: Linear systems, row reduction to echelon form (reading: Sections 1.1-1.2)
- Week 2: Vectors, matrix equations, linear independence (reading: Sections 1.3-1.5, 1.7)
- Week 3: Linear independence, linear transformations (reading: Sections 1.7-1.9)
- Week 4: Matrix multiplication, the inverse of a matrix (reading: Sections 2.1-2.3)
- Week 5: Subspaces, bases, dimension (reading: Sections 2.4, 2.8-2.9)
- Week 6: Determinants (reading: Sections 3.1-3.2)
- Week 7: Vector spaces, midterm (reading: Sections 4.1-4.6)
- Week 8: Eigenvectors, and eigenvalues (reading: Section 5.1)
- Week 9: Similarity and diagonalisable matrices (reading: Sections 5.2-5.4)
- Week 10: Complex eigenvalues, properties of eigenvalues (reading: Sections 5.5, 6.1)
- Week 11: Inner products, orthogonality, and projections (reading: Sections 6.1-6.3)
- Week 12: Gram-Schmidt process, least-squares problems (reading: Sections 6.4-6.6)
- Week 13: Symmetric matrices, SVDs (reading: Sections 7.1, 7.4)