Math 2085-Section 1 Information For Fall 2023

Time MWF 10:30 AM -- 11:20 PM
Location Room: 134 Lockett.
Calendar Our class meets from Monday August 21 through Friday December 1. The Final Exam will be Tuesday, Dec.5, from 3:00pm - 5:00pm
Leonard Richardson Office 386 Lockett

Office Hours

  1. MWF 11:30 AM -- 1 PM in person in my office, 386 Lockett Hall.
  2. TTh online only, at this Zoom link: by arrangement only. Email me if you would like an appointment for online Zoom office hours on Tuesday or Thursday.
I am available at many other times. Email first to make sure I'm able meet with you. I answer email many times daily---usually quickly.
Telephone 578--1568
Graduate Assistant Mr. Adi Pandikkadan (Email: will grade your collected homework assignments. If you are absent on a day when homework is due, please email your assignment directly to the grader! He will be available to answer questions about the grading of your homework in room 329 Lockett from 12:30 PM -- 1:30 PM on Wednesdays.
Text Otto Bretcher: Linear Algebra with Applications, Fifth edition (Classic Version), Pearson, 2019. The bookstore ISBN is: Print (paperback): 9780135162972 USE ONLY this ISBN for your printed book. Every mathematics student should have the printed book because you can keep it permanently in your personal library. This is important because linear algebra is vital to every branch of both pure and applied mathematics. There are many used copies available also: Just be sure to buy the 5th edition.
Caution: There is a new type of e-text available for a fee according to the duration of your access to it on the Pearson website. I urge you very strongly NOT to use this! Last year students who downloaded this received different files with serious errors. This e-text is reconstructed from files each time a student downloads it, and sometimes the files load incorrectly and are mangled. In effect, if you use this you are using a copy that is not proof-read and that cannot be proof-read because it loads unreliably. The Web software that loads the files is faulty. The publisher hopes that the software has been fixed, but I am unaware of any proof of this. Stick to the printed book, whether new or used. Buy only from reputable sellers.
We plan to cover most of Chapters 1 -- 7. This course treats systems of linear equations, vector spaces, linear transformations, matrices, and determinants.
Prerequisites MATH 1552 or 1553. It is particularly important to be fluent with vector algebra from second semester calculus. Credit will not be given for both Math 2085 and MATH 2090.
Free Math Tutoring Your first resource should be to see me. I look forward to helping students individually in my office. There are also other resources:
The Shell Tutorial Center will open its doors on TBA, in ROOM 141, Middleton Library.
HOURS of Operation: M-Th, 9:30 AM to 7:00 PM. Friday, 9:30 - 3:00 pm.
FOR More information on tutoring in all subjects go to:
CAS also offers many on-line student resources such as study tips, time management, etc. CAS is located in B-31 Coates Hall.
CAUTION: There have been reports of unauthorized persons advertising tutoring services on campus and even in classrooms by circulating sign-up sheets. Be careful! The University does not authorize or recommend such services and advertising for such services is not permitted in our classroom. If you see advertising for such services in our classroom, please let me know.

Special Instructions during Public Health or Safety Emergencies

Your health and safety are our top priority. If you are feeling ill please contact the LSU Student Health Center for medical advice. If you are experiencing excessive stress, the Student Health Center offers mental health support as well. And please observe all the University's requirements and recommendations during emergency conditions.

We have learned from recent years that there can be unexpected changes due to the unpredictable nature of emergencies such as pandemics or extremes of weather, so that the format of the course and/or requirements may be forced to change, and if this is the case we will take care to ensure that every student is treated in a fair and considerate manner. If you have any special individual difficulty, please contact me quickly so that I can do anything possible to assist you. That said, we are looking forward to the fall semester and hoping that it will be smooth sailing.

With regard to class attendance, if you don't feel well, check with the Student Health Center and follow their advice about whether or not to come to class.

Organization of this Class

Homework will be assigned daily. Homework problems to be collected for grading will be indicated in red boldface. Please understand that it is from the effort of working your way through assigned problems on paper that you learn mathematics.
It is by no means sufficient to read solutions in a solutions manual! You must work out problems yourself, the hard way, in order to learn this work.
Do not become a victim of the online scoundrels who will sell you solutions for a few dollars a month. They do not care about the quality of your education, and they will not help you if the result is that you need to repeat the course and pay tuition a second time for the same course.
Examination problems will be very similar to assigned homework problems. Thus your daily effort on homework problems will be strongly reflected in your test grades.


These will be closed-book tests. You must keep your eyes on your own paper and do your own work. Do not communicate with your classmates during an examination. No books or notes are permitted, electronic, paper, or on any other medium. No electronic devices are permitted other than a calculator and a watch to check the time. No cell phones, smart phones, or internet-connected devices are permitted.
The problems will be similar to those in the homework: those that are collected and also those that are not collected. A correct answer is not sufficient to receive credit. You must show all the work that leads correctly to the solution.

Attendance is required.

Your presence and participation in class is an essential part of this course. Most LSU students are conscientious and sensible about coming to class unless there is a serious, excusable reason for not being able to do so. However, there is an unfortunate tendency for some students to become discouraged as the term progresses and to cease regular attendance. This happens despite the fact that a student who is feeling discouraged has an especially great need to be in class and to ask questions. The attendance policy is intended to ensure that every student comes to class even when the going gets tough.
If you need to be absent you must tell me why so that I can determine whether or not such an absence is excused. Depending on circumstances I may require documentation for your absences and documentation will always be required if you are absent from an hour test or from the Final Examination.

Lateness and Classroom Conduct

Please try to arrive on time for class. But sometimes it may be unavoidable to be late. If you are late, please come right into class, doing so as quietly as you are able so as not to disturb other students. I do not want you to wait outside in the hall. You should have as much classroom time as possible, so please just come in--quietly--and take a seat even if you are late. Class time is a time for work. So when class begins please put away all cell phones, smart phones, head phones, wrist watch communicators, tablets, laptops, etc, and turn your attention to the work of the class. Thank you.


There will be three hour tests, worth 100 points each, and a two hour final examination, worth 200 points. Your percentage correct for the collected homework problems will count as a fourth hour test worth 100 points. Your lowest hour test grade will be replaced by half of your 200-point final exam score, if it is to your advantage. I will grade your hour tests and your final exam and return the hour tests to you the very next class meeting each time. Your test average will be the sum of all your hour test grades, your final exam grade , and your homework grade as a percentage divided by 6, since 600 will be the maximum possible number of points. So your test average, expressed as a percentage, will be less than or equal to 100. The minimum grade for each letter grade is as follows:
A+, 97
A, 93
A-, 90
B, 83
B-, 80
C+, 77
C, 73
C-, 70
D+, 67
D, 63
D-, 60
F, below 60
You should save all your graded work for future study and in case you think your final grade is in error.

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It is important not to fall behind. It is very important to attend class and participate in homework discussions daily. Please do not assume you can take care of difficulties later---see me for help as soon as possible if there is something you do not understand! You are responsible for all assigned problems---not just those which we go over the next day!

Homework Assignments and Downloads

The table of assignments below needs to be revised for the current semester. You will know an assignment is correct for this semester when the due date has been inserted. Be sure to reload this page from the website each time you visit, since it will be updated daily!

Homework problems to be collected for grading will be indicated in red boldface. This homework will be part of your final average! Homework must be turned in on time. If you have done your homework but for some reason could not come to class, you may scan your homework and send the file (pdf preferred) directly to the grader using the link provided higher on this page. You should keep a notebook with all your solutions written out, including those problems that are not collected. We will reserve some class time each day to answer questions about the homework that is due for that day. Test questions will resemble assigned homework problems, so it is important to put in the time and effort to keep up with the daily homework. The homework grader will also have office hours to answer questions, as posted above.

The University has clear policies requiring academic honesty. If you email me about a pending assignment, I may send a hint to the whole class in answer to your question, not giving your name of course! If on the other hand you get a good idea from another book, or from talking with a friend, academic honesty requires that you acknowledge your sources openly. Above all, never copy directly from another person's written work as though it were your own. Remember that your own good name is irreplaceable. This is a sound principle which will serve you well throughout your life. Moreover, on a practical level, it is very foolish claim another person's work as your own. Work that is copied can be recognized very easily.

Due Assignments
August 21 Read this syllabus so you can ask questions about it in class. Obtain a copy of the text so that you are ready to begin work. If you have been away from mathematics courses for a few years, it may be necessary to review what you learned during your earlier courses.
August 23 1.1 / 1, 5, 9, 11, 13, 15, 17, 19, 21, 37, 39.
August 25 Please hand in: 1.1 / 20, 22. Write your solutions neatly, so the grader can read them easily, numbering each problem in order. PRINT your name clearly at the top of your paper so that you will receive the proper credit.
August 28 1.2 / 1 -- 5, 11, 19, 26, 27, 29, 36, 37, 47.
August 30 1.2 / 28, 38. For #28, please give a reason for your answer.
September 1 1.3 / 1 -- 3, 5--9(odd), 15, 17, 19, 22, 25, 29, 35, 59.
September 6 1.3 / 24, 30, 36 .
September 8 2.1 / 1-3, 5, 7, 9, 15, 17, 19, 21.
September 11 Please hand in 2.1 / 4, 6, 44.
September 13 2.2 / 2, 3, 5, 6, 10, 19, 21.
September 15 Please hand in 2.2 / 14. ALSO: 2.2 / 7, 8, 11, 13, 15.
September 18 Please hand in 2.2 / 16b. . Also: 2.3 / 1--13 (odd).
September 20 2.3 / 17, 19, 29, 33, 35, 37, 43, 47.
September 22 Please hand in 2.3 / 18, 44, 46 .
September 25 2.4 / 1 -- 11 (odd), 17, 21, 23, 29, 31, 35, 55, 57, 59, 82--84, 86. Today I cannot be in class, but I have recorded a one hour lesson for you on Zoom to view at your leisure instead of coming to the classroom on Monday. I will be back in class on Wednesday, however. Here is the link: This Zoom talk was recorded by me a year ago, but it turns out to be exactly the right topic for this year. I hope you will enjoy it. PLEASE NOTE: ZOOM DELETED THIS FILE AFTER I POSTED THE LINK. BUT I HAVE RECOVERED THE DELETED FILE AND IT IS WORKING NOW AND IS SUPPOSED TO WORK FOR THE NEXT 30 DAYS! SO IF YOU COULDN'T ACCESS THIS BEFORE, PLEASE TRY AGAIN!
September 27 Please hand in 2.4 / 4, 32, 40.
September 29 Bring Questions to Review for the First Hour Test, covering sections 1.1 --2.4, inclusive. Everyone is expected to make a written list of questions! If you cannot think of any questions for review for the hour test, then do the following assignment instead: 3.1 / 1, 3, 5, 9, 15, 17, 19, 33, 35 and ask questions about it.
October 2 First Hour Test today.
October 4 Please download and read carefully the Hour Test #1, Fall 2023, Solution Sketches and Class Statistics. Also: 3.1 / 1, 3, 5, 9, 15, 17, 19, 33, 35.
October 9 Please hand in 3.1 / 16, 18 .
October 11 3.2 / 1 -- 9, 11, 15, 17, 23, 27, 29, 37, 39.
October 13 Please hand in 3.2 / 16, 34. General Note: If the zero vector is included in a set of vectors, it is a linearly dependent set. This is the case in exercise 18, for example. Linear independence of a set of vectors has nothing to do with the order in which the vectors are listed, and the author's definition of redundancy breaks down if the zero vector happens to be listed first. So in problems in this text, you should count zero vectors as redundant, although superfluous might be a better choice of word.
October 16 3.3 /1, 3, 5, 9, 13, 17, 21, 27, 29, 31, 33, 35 .
October 18 Please hand in 3.3 / 28, 30, 36. Today's lesson about change of basis and similar matrices is very important!
October 20 Today's lesson about change of basis and similar matrices is very important!
October 23 3.4 / 1, 3, 7, 9, 11, 13, 15, 17, 19, 21, 23, 31, 37, 41, 43. Use just the method (a) in the homework instructions: that is use the change of basis matrix to find the matrix of T with respect to the new basis.
October 25 Please hand in 3.4 / 20, 26, 38. Note: In each problem, it is sufficient to solve the problem correctly using any one method. Try to pick the method that will be easiest to apply. In problem 38, please be sure to show also the matrix of the linear transformation in the new basis you have chosen.
October 27 Bring questions to review for the second hour test!
October 30 Hour Test #2. This test will cover Chapter 3 in our text.
October 31 Please download and read carefully Hour Test #2, Fall 2023, Solution Sketches and Class Statistics.
November 1 4.1 / 1, 3, 5, 7, 9, 11, 17, 19, 21, 23, 25, 27.
November 3 Please hand in 4.1/ 20, 30.
November 6 4.2 / 1, 3, 5, 7, 13, 15, 17, 19, 23, 25, 27, 45, 51, 59, 61.
November 8 4.2 / 10, 28, 52.
November 10 4.3 / 1, 3, 5, 7, 13, 21, 23, 25, 35, 41, 47.
November 13 4.3 / 1, 3, 5, 13, 21, 23, 25, 35, 41, 47.
November 15 4.3 / 8, 42. Also: 5.1 / 1-3, 5--9(odd), 15, 25, 29, 31, 41.
November 17 5.1 / 12, 16, 42.
November 20 5.2 / 34. Also: 5.2 / 1, 5, 9, 13, 33, 35.
We will be presenting a different way of understanding the determinant on Monday, so please don't miss class.
November 22 6.2 /11, 13, 15, 47, 51. Use what we learned on Monday to answer these questions.
Bring questions to review for the third hour test.
November 27 Third Hour Test today! This test will cover assignments that were due before today but since the second hour test.
November 27 Please download and read carefully the Hour Test #3, fall 2023, Solution Sketches and Class Statistics.
December 1 6.2 / 1--9 and 6.1 / 18, 26.
December Bring questions to review for the Final Exam! Don't forget to review from the beginning of the course!
Please remember to fill out your course evaluation forms online.
Study for the Final Exam! This 200-point exam will cover the whole course in a uniform manner, so remember to review from the beginning of the course. Coverage on the Final Exam runs from the first assignment through the last assigned problem.
Your final grade for the course will be the larger of the following two:
1. The grade guaranteed by the formula provided higher on this page.
2. One letter below the final exam grade. For example, if your final exam grade is A-, you are guaranteed at least a B- in the course.
Thus the final exam provides a safety net that supplements the calculations specified above.
December 4 -5 Final Exam Week Office Hours:
I will have office hours Monday from 3PM to 4PM and Tuesday from 1PM to 2PM.

December 5 The Final Exam will be Tuesday, Dec.5, from 3:00pm - 5:00pm in our regular classroom.
December Please download and read carefully the Final Examination, Fall 2023, Solution Sketches and Class Statistics.