Math 201, Fall 2019

Instructor:        Jingjun Han

TA:                 Daniel Fuentes-KeuthanEmily QuinanYujie Luo
Office:                Krieger 220
Office Hours:     MW 10:50-11:50 AM, W 3:00-4:00 PM in Krieger 220
Lectures:             MWF 10-10:50 Maryland 110
Textbook:           Linear Algebra with Applications, 5th Edition, Otto Bretscher, Prentice Hall, December 2012




      Midterm 1:  Friday Oct 4, 10-10:50
      Midterm 2:  Friday Nov 8, 10-10:50
      Final         :  Monday Dec 16, 9-12


Homework. The solutions are provided by Daniel Fuentes-Keuthan (HW1, HW4, HW7), Emily Quinan (HW3, HW 6, HW9)Yujie Luo (HW2, HW5, HW8)


HW1. 1.1: 9, 11,15,20,21                           optional: 1.1:41,45,47,49.    Solution.


HW2. 1.2: 5,38,47; 1.3: 4; 1) If a linear system has exactly one solution, show that the number of variables is less than or equal to the number of equations. Provide an example such that the number of variables is equal to (less than) the number of equations, respectively. 2) A linear system with fewer equations than unknowns (n<m) has either no solutions of infinitely many solutions. Provide an example such that the linear system has no solution (infinitely many solutions.).           optional: 1.2: 4,7,48; 1.3: 10,13,19,24,27,28,37,46,52,69; Solution.


HW3. 1.3: 47; 2.1: 7,13,50; 2.2:29. Optional: 2.1:1,3,5,32,40,44,48,53. Solution.

HW4. 2.2: 5,12; 2.3: 14,32,81.                             Optional: 2.2: 10,14,33,38; 2.3:1,3,13,65,66,84,85. Solution.

HW5. 2.4: 30, 54; 3.2: 6;                                                     

1. Show that a square matrix A is invertible if and only if ker(A) is the zero vector.

2. Let w1=(a,b), w2=(c,d) be two vectors, such that they are not in the same line. Find x,y,z,t such that e1=xw1+yw2,e2=zw1+tw2, where e1=(1,0), e2=(0,1).


Optional: 2.4: 8, 20, 29, 32, 33, 44,68,69,76; 3.1: 7, 21, 42, 50; 3.2: 3, 5, 7.     Solution.


HW6. 3.2: 37; 3.3: 28, 33; 3.4:38, 58.                                           optional: 3.2 :36, 42, 48, 54; 3.3: 22, 29, 33, 39; 3.4: 19, 41, 52, 54, 56, 69, 80. Solution.


HW7. 4.1: 40, 54; 4.2: 10, 55, 67.                                                 optional: 4.1: 19, 25, 27, 41, 60; 4.2: 4, 5, 11, 52, 63, 68, 69, 71. Solution.


HW8. 4.3: 4, 40, 59, 60, 68.                                                          optional: 4.3: 3, 5, 20, 38, 48, 54, 61, 66, 70, 71.  Solution.


HW9. 5.1: 16, 23. 5.2: 8, 28, 35.                                                   optional: 5.1: 8, 11, 12, 17, 18, 21, 31; 5.2: 31, 32, 33, 38, 45.


HW10. 5.3: 27,33,45,46,60.                                                          optional: 8, 32, 44, 48, 55, 66, 67, 69, 71, 73, 74. 


Practice Midterm1, Solution. Midterm1, Solution.

Practice Midterm2, Solution. Midterm2, Solution.


Your grade

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

The exams in this course will be difficult.

There will be no curve for the class and the final grade will only depend on your position in the class. In usual, A: 30%-40%, B: 30%-40%.





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 final exam. Excused absences from midterms will only be permitted with a letter from the Academic Advising Office. No excused absences are allowed from the final exam. If you have conflicts on the final exam, the department will notify you the adjusted dates to take the final exam.

Graded exams will be returned in section. When you receive a graded exam, please take the time to review the grading and scoring to confirm that no errors have been made. Do this before you leave the classroom. If you take your exam out of the room, it will be assumed that you accept the grade, and under no circumstances will the grade be changed. If you need additional time, please return your exam to your TA and schedule a time to continue your review. If you want to regrade the exam, TA will regrade ALL of the problems in the exam, and it is not always the case that you will receive a higher grade.


TA’s office hour: Daniel Fuentes-Keuthan Monday 2-3 pm, Yujie Luo Thursday afternoon 4pm-5pm, Emily Quinan Mondays from 1:30-2:30pm.





Problem sets will generally be posted here each week before Friday (start from the first week), and you need to submit it in the section next week. The following rules apply to homework:


Special aid:
Students with disabilities or other special needs that require classroom accommodation or other arrangements must let the instructor know at the beginning of the semester.

Academic support:

General policies:

The strength of the university depends on academic and personal integrity. In this course, everyone must be honest and truthful. Violations include cheating on exams, plagiarism, reuse of assignments without permission, improper use of the internet and electronic devices, unauthorized collaboration, alteration of graded assignments, forgery and falsification, lying, facilitating academic dishonesty and unfair competition. Ignorance of these rules is not an excuse.
For more information see the guide on "Academic Ethics for Undergraduates" and the Ethics board website ( for more information.

In this course, as in many math courses, working in groups to study particular problems and discussing theory is strongly encouraged.  Your ability to talk mathematics is of particular importance to your general understanding of mathematics. You can discuss with other students about how to approach the problem.  However, you must write up the solutions to the homework problems individually and separately.  If there is any question as to what this statement means, please see the instructor or the TAs.