Math 2121 (Fall 2023)
Overview
Welcome to the homepage for Math 2121: Linear Algebra!
- Send questions for the instructor to emarberg@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, in LTC
- L2: Tuesdays & Thursdays, 09:00 - 10:20, in LTD
New lecture notes will be posted each Friday. Try to read these before each class.
Week 1:
Week 2:
Week 3:
Week 4:
Week 5:
Week 6:
- Lecture 11: Introduction to determinants
- Lecture 12: Properties of determinants [demo]
- No graded Practice Problems in Week 6 (prepare for midterm instead)
Week 7:
Week 8:
Week 9:
Week 10:
Week 11:
Week 12:
Week 13:
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.
- These assignments will be due on Mondays at midnight, starting 11 September.
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.
- Each week, choose four practice problems and write down solutions.
- You can earn extra credit by solving more practice problems. See the instructions.
- These assignments will be due on Wednesdays at midnight, starting 13 September.
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 an 80 minute, in-class midterm on Tuesday, October 17.
The exam will be closed book, closed notes,
with no calculators or other electronic devices allowed.
- Date: October 17
- Time: (your lecture period)
- Location: (your lecture classroom)
The midterm will cover Lectures 1-12 and HW 1-6.
Review problems and practice exams:
Note that most of these practice exams are designed to take 120 minutes.
Our 80 minute midterm will be a little shorter than these tests.
Here are solutions to the L1 midterm.
Here are solutions to the L2 midterm.
Final
We will have a cumulative 3-hour final exam.
- Date: 18 December
- Time: 8:30AM - 11:30AM
- Location: S H Ho Sports Hall
The format will be similar to the midterm.
The exam will be cumulative, covering all lectures and homework.
Review problems:
Practice exams:
Here are the solutions to our final.
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)