# Mate1009: Algebra (Spring 2020)

Instructor: Mārtiņš Kālis
E-mail: martins@kalis.lv
Lectures: Wednesdays, 12.30–14.10, room 426 (auditorium 20) MS Teams
Office hour: Tuesdays, 9.00-10.00, room 434 MS Teams

Exam 3 June 2020 (retake option 17 June 2020), 12.30–14.10 on MS Teams.

Lecture 14 (13 May 2020). Polynomial roots and factors (p. 132–166) in lecture notes. The lecture will be recorded and available on MS Teams.

Lecture 13 (6 May 2020). Basics of polynomials (up to and including polynomial division)
The lecture will be recorded and available on MS Teams.
Quiz #3 on complex numbers will take place at the beginning of lecture.

Lecture 12 (29 April 2020). Complex numbers: Argument of complex numbers (5.6), De Moivre’s theorem (5.7).
The lecture will be recorded and available on MS Teams.
Quiz #3 on complex numbers will take place at the beginning of lecture 13, May 6, 12:30. Please let me know if you are not able to join at this time.
– Practice problems: problems 5, 6, 7, 8 from section 5.8.
Additional resources, useful to freshen up or catch up on the basics:
Trigonometry fundamentals | Lockdown math ep. 2 | 3blue1brown
Complex number fundamentals | Lockdown math ep. 3 | 3blue1brown
More on e^iπ=-1 (this is outside of the scope of this course).

Lecture 11 (22 April 2020). Complex numbers: complex conjugate (5.4), modulus of a complex number (5.5, up to, excluding Apollonius circles)
Please read sections 5.4 and 5.5 (up to, excluding Apollonius circles) from the lecture notes.
The lecture will be recorded and available on MS Teams.
– Practice problems: problems 5 (find just the modulus, not the principal argument), 9, from section 5.8.

Lecture 10 (15 April 2020). Complex numbers.
If you are not familiar with complex numbers or need a refreshment, please watch the following video: Complex Numbers: Part Imaginary, but Really Simple by Dr. Strang.
– Practice problems: problems 1, 2, 3, 4 from section 5.8.

Lecture 8 (25 March 2020) & Lecture 9 (1 April 2020). Determinants.
– Practice problems: problems 4, 5, 8, 9, 11, 14 from section 4.1. (the other problems from the section are helpful, but optional).
– Cramer’s Rule, Inverse Matrix, and Volume, MIT 18.06, Lectures 18, 19, 20
– “Linear algebra and its applications”, Gilbert Strang, chapter 4 (Determinants). available in the library.

Midterm-homework. The midterm graded homework replaces Quiz #2 and midterm exam scores for the final grade. The deadline for submissions ir 5 April 2020, 23:59.
Edit 2020-03-25: 2(c) should read Solve A⃗x = b for (i) a = 1, bc = 1, (ii) a = 1, bc = 0, (iii) a = 0, bc = 1.

Lecture 7 (18 March 2020). Independent study. Please read sections 2.5 and 2.6, and do the practice problems below.
– Practice problems: problems 1, 3, 4, 9, 11, 13, 22 from section 2.7. (the other problems from the section are helpful, but optional).
– 3blue1brown series “Essence of linear algebra“, episodes 6 & 7 (shared with lecture 6), episode 12.
Projection Matrices and Least Squares, MIT 18.06, Lecture 16
Cramer’s Rule, Inverse Matrix, and Volume, MIT 18.06, Lecture 20
– “Linear algebra and its applications”, Gilbert Strang, section 3.3. (Projections and least squares), available in the library.

Lecture 6 (11 March 2020). Matrix recurrence relations (2.3), Non–singular matrices (2.5).
– Practice problems: problems 2–5 from section 2.4. (the other problems from the section are helpful, but optional).
– 3blue1brown series “Essence of linear algebra“, episodes 6 & 7 (shared with lecture 7).
Multiplication and Inverse Matrices, MIT 18.06, Lecture 3
– “Linear algebra and its applications”, Gilbert Strang, sections 1.6. (inverses and transposes), 2.2. (Solving Ax=0 and Ax=b), available in the library.

Lecture 5 (4 March 2020). Matrices. Linear transformations.
– Practice problems: problem 1 from section 2.4
– 3blue1brown series “Essence of linear algebra“, episodes 1–5.
– “Linear algebra and its applications”, Gilbert Strang, section 1.4., available in the library.

Lecture 4 (26 Feb 2020). Field axioms. Matrices.
– Practice problems: 12, 13 (Chapater 1), example 2.1.2., problem 1 from section 2.4.

Lecture 3 (19 Feb 2020). Homogeneus systems of equations. Arithmetic modulo p. Field axioms.
Jupyter notebook from the lecture.
– Practice problems: 6, 7, 8, 9, 11 (Chapater 1)
– Optional: 14, 15, 16
– There will be a 30 minute quiz on Chapter 1 (except Field axioms) during the next lecture.

Lecture 2 (12 Feb 2020). Gauss-Jordan method.
Jupyter notebook from the lecture.
– Practice problems: 3, 4, 5 (Chapater 1)
Elimination with matrices, MIT 18.06, Lecture 2
– “Linear algebra and its applications”, Gilbert Strang, section 1.3., available in the library.

Lecture 1 (5 Feb 2020). Introduction, (reduced-)row-echelon form, elementary row operations. Chapter 1 in course materials.
– Practice problems: 1, 2 (Chpater 1)
Column / row picture (will not be covered in depth), MIT 18.06, Lecture 1
Elimination with matrices, MIT 18.06, Lecture 2
– “Linear algebra and its applications”, Gilbert Strang, section 1.3., available in the library.

Exams: There will be 4 quizes (M1a, M1b, M2a, M2b – out of 5), 1 midterm exam (P1 – out of 10), 1 midterm graded homework (MT – out of 32) and 1 final exam (P2 – out of 1050). You can retake the quizes and exams once.
Attendance bonus: For each fully attended class, 1/4 bonus point will be received. (Maximum: 16/4 = 4 points)
Your grade (out of 100) = bonus + 1.25(M1a+M1b+M2a+M2b) + 2.5P1 MT + 5P2
To pass the course, you must get at least 4 points 40% in each — the midterm and the final exam.