Math 201: Linear Algebra
Spring 2018, MWF 10-10:50 AM or 11-10:50 AM
Krieger 205

Instructor: J. Specter
jspecter at jhu dot edu

Welcome to Linear Algebra! You've found the course website. This is the syllabus. Below you'll find important information about the content, structure and logistics of the course. Please take the time to read it carefully.

### What is this course about?

This course is about Linear Algebra.

### The text

Linear Algebra with Applications, Fifth Edition, Otto Bretscher. ISBN: 978-0321796943

Your grade for this course will be calculated as the weighted average of your grades on the weekly homework assignments (15%, lowest HW grade dropped), weekly quizes (5%, lowest quiz dropped), a pair of midterms (20% each), and a final exam (40%).

### Exams

There will be three exams in this course. Two in class midterms:

Midterm Exam 1: Monday, March 4,

Midterm Exam 2: Monday, April 15

and a comprehensive final exam:

Final Exam: 9-12 Noon, Thursday, May 9.

Review Session: Sunday, May 5 at 6:30 pm in Kreiger 205 (where we have class)

All exams will occur in Kreiger 205. Please bring your ID to all exams. Exams must be completed in blue or black pen. The use of textbooks, notes, and calculators will not be permitted.

No make-up exams will be offered in this course. If you have to miss an exam for a documented, legitimate reason, then your final grade will be calculated using your other exam grades.

### Lecture Notes

Scanned copies of the lecture notes can be found here.

Lecture 6, Dot Products and Orthogonal Projections (Suggested reading: pg. 61-66 in 2.2.)

Lecture 7, Matrix Multiplication (Suggested reading: pg. 75-81 in 2.3.)

Lecture 8, Invertible Matrices (Suggested reading: pg. 88-95 in 2.4)

Lecture 9, Solving Ax = b (Suggested reading: Section 3.1)

Lecture 10, Subspaces of R^n. (Suggested reading: Section 3.2)

Lecture 11, Bases and Dimension (Suggested reading: Section 3.2 p. 128-30; Section 3.3)

Lecture 12, The Rank-Nullity Theorem (Suggested reading: Section 3.3)

Lecture 13, Coordinates (Suggested reading: Section 3.4)

Lecture 14, Similar Matrices (Suggested reading: Section 3.4, pg. 156-159; Section 2.4 on Inverting a 2x2 matrix pg. 93-95)

Lecture 15, Orthogonality and Projection in R^n (Suggested reading: Section 5.1 up to pg. 211)

Lecture 16, Projection and Orthonormal Bases (Suggested reading: Section 5.1 pg. 203-209; Section 5.2 pg. 218-221 (On Gram-Schmidt Process) )

Lecture 18, Orthogonal Transformations (Suggested reading: Section 5.3)

Lecture 19, Application: Curve Fitting (Suggested reading: Section 5.4, pg. 241-245)

Lecture 21, Determinants I: Computing the Determinant (Suggested reading: Section 6.2)

Lecture 22, Determinants II (Warning! There is a subscripting error in these notes on page 19. The subscripts should {i,1} and not {1,i}). Suggested reading: Section 6.3)

Lecture 23, Diagonalization (Suggested reading: Section 7.1)

Lecture 24, Finding the Eigenvalues of a Matrix (Suggested reading: Section 7.2)

Lecture 25, Finding the Eigenvectors of a Matrix (Suggested reading: Section 7.3)

Lecture 26, Matrix Powers and Dynamical Systems (Suggested reading: Section 7.1 pg. 316-323; See Section 7.4 for additional examples)

Lecture 27, Complex Eigenvalues (and Eigenvectors) (Suggested reading: Section 7.5 (review complex numbers: pages 363-367))

Lecture 29, Matrix Powers with Complex Eigenvalues II (See Theorem 7.5.3 and Example 3 of 7.6)

Lecture 30, Symmetric Matrices (Suggested reading: Section 8.1)

Lecture 31, Quadratic Forms I (Suggested reading: Section 8.2. This lecture will focus on quadratic forms in 2 variables.)

Lecture 33, Singular Value Decomposition (Suggested reading: Section 8.3)

Lecture 36, Review: Graphing Quadratic Forms

### Homework

Homework accounts for 15% of the grade for this course. It will be assigned weekly, and your homework grade will be the average of your weekly assignments. Homework is due at the beginning of class on its posted due date. Most weeks, assignments will be posted on Friday and will be due on the following Friday. Homework must be written legibly and stapled when necessary. No late homework will be accepted.

You are encouraged to talk to your classmates about the material covered in class and collaborate on homework. However any assignment you pass in must be primarily your own work. To avoid the pitfalls of plagiarism, please write up your assignments alone and independently. If you've worked on a problem with another student, please acknowledge that collaboration in your write up (of that problem).

Homework assignments will appear weekly - posted to the following table.

Week 2 1.1: 12,14,16,43;
1.2: 6, 10, 12;
1.2: 30,48, 50;
1.3: 1, 22.
Solutions
Week 3 1.3: 16,18,19,35,36;
2.1: 6, 24, 26,42;
2.2: 2, 6, 7, 16, 32, 36.
Solutions
Week 4 2.3: 7, 8 (you may alternatively do 2.1: problem 13), 29, 30, 38;
2.4: 1, 6, 8, 14, 28;
3.1: 6, 15, 24, 34 (Hint: use projection), 42.
Solutions
Week 5 3.1: 20,21,41;
3.2: 5,6,7,30,42,46;
3.2: 14,20,26;
3.3: 24,25,28,39.
Solutions
Quiz 4 Solutions
Week 6 3.4: 4, 6, 16, 18, 26, 28, 30, 38, 39, 56, 60, 67. Solutions
Quiz 5
Week 7 5.1: 4,6,11,26,28.
5.1: 40,41,42,43,44,45,46.
5.2: 2,6,14,29,34.
Solutions
Week 8 5.3: 2,4,36,40,43,67,69,70.
5.4: 2,9,22,24,26,30,32,36.
Solutions
Week 9 6.2: 2, 4, 6, 8,40, 44, 46, 66
6.3: 1, 2, 3, 4 , 7, 14, 29, 47.
Solutions
Week 10 7.1: 15, 16, 18, 56, 62;
7.2: 2, 10, 12, 15, 16, 32;
7.3: 4, 6, 14, 18, 20, 52;
Bonus: 7.3, 54.
Solutions
Quiz 8 Solutions
Week 11 7.1: 72;
7.4: 4, 6, 10, 12, 26, 34, 38;
7.5: 9, 20, 22, 24, 30;
7.5: 33, 34; (these two problems will be among those graded)
Solutions
Week 12 7.5: 14, 16, 17, 48;
7.6: 32, 41;
8.1: 6, 8, 22, 26, 42;
8.2: 3, 6, 18, 20, 27, 38;
Solutions
Week 13 8.3: 7,8,10,12,14;
Bonus Problem
Solutions Quiz9 Solution

Remember to show both your work and your reasoning on your homework solutions. The DUS Rich Brown has written a wonderful note on homework presentation which you can find here.

### Sections, Quizzes, and Office Hours

The goal of the section meetings is to help you bring the theory presented in the lectures into practice. Please come with questions! Graded homework will be passed back during section meetings so it is important that you attend only the section assigned to you.

Meeting Times Location Instructor Email: < >@jhu.edu
Section 1 Tuesdays 3:00-3:50 Shaffer 100 Benjamin Dees bdees1
Section 2 Tuesdays 4:30-5:20 Hodson 211 Patrick Kennedy pkenne16
Section 3 Thursdays 1:30- 2:20 Hodson 316 Patrick Kennedy pkenne16
Section 5 Tuesdays 1:30-2:20 Hodson 316 Jeff Marino jmarino9
Section 6 Tuesdays 3-3:50 Maryland 309 Jeff Marino jmarino9
Section 7 Thursdays 3:00-3:50 Hodson 203 Xiangze Zeng xzeng12
Section 8 Thursdays 4:30- 5:20 Hodson 211 Xiangze Zeng xzeng12

During each section meeting you'll be given a short quiz. These quizzes account for 5% of your grade.

In addition to the sections each of the TA's and myself will hold weekly office hour.

My office hours are:
J. Specter: Wednesdays 12:15 - 1:45 in Krieger 419 or by appointment.

TA office hours:

Marino: Thursdays 12-1 in Krieger 200. Help room Wednesday 11-1.

Kennedy: Wednesdays 5-7 in Krieger 207.

Dees: Thursdays 3-4 PM in Krieger 201. Help room hours are 11-1 on Mondays

Zeng: Thursdays 11am-1pm in Krieger 213.

• Math Help Room. Located in 213 Kreiger Hall -- check link for schedule. Offers additional help from math graduate students.
• PILOT Learning. A peer-lead team learning program.
• The Learning Den. Free tutoring offered by the university.

### Students with disabilities

Students with documented disabilities or other special needs who require accommodation must register with Student Disability Services. After that, remind the instructor of the specific needs at least two weeks prior to each exam; the instructor must be provided with the official letter stating all the needs from Student Disability Services.

There may be a student in this class who requires the services of a note taker. This is an opportunity to share notes through the Student Disability Services Office. If you are interested in performing this service, please register as a notetaker with Student Disability Services via the following URL: https://york.accessiblelearning.com/JHU/

### JHU ethics statement

"Undergraduate students enrolled in the Krieger School of Arts and Sciences or the Whiting School of Engineering at the Johns Hopkins University assume a duty to conduct themselves in a manner appropriate to the University's mission as an institution of higher learning. Students are obliged to refrain from acts which they know, or under circumstances have reason to know, violate the academic integrity of the University. [The JHU Code of Ethics]"

Ethical violations include cheating on exams, plagiarism, reuse of assignments, improper use of the Internet and electronic devices, unauthorized collaboration, alteration of graded assignments, forgery and falsification, lying, facilitating academic dishonesty, and unfair competition.

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