LSU College of Science

Math 2085 Information

For Spring 2019

Time MWF 11:30 AM -- 12:20 PM
Location Room: 112 LOCKETT.
Calendar Our class meets from Wednesday, January 9, 2019 through Friday, April 28, 2019. The Final Exam will be Tuesday April 30, 12:30- 2:30 PM.
Leonard Richardson Office 386 Lockett
Office Hours MWF 12:30 -- 1:30 PM and TTh 1:30--2:30 PM. I am available at many other times. Email or call first to make sure I'm able meet with you. I answer email many times daily.
Telephone 578--1568
Graduate Assistant Mr. Vishnu Sivaprasad will grade your collected homework assignments. He will be available to answer questions about the grading of your homework in room 345 Lockett from 3PM - 4PM Tuesday and Thursday.
Text Otto Bretcher: Linear Algebra with Applications, Fifth edition, Prentice Hall, 2013. We plan to cover most of Chapters 1 -- 7. This course treats systems of linear equations, vector spaces, linear transformations, matrices, and determinants. CAUTION!! There are illegal pdf copies of this text available free online but prepared with incorrect fonts with the result that the text reads incorrectly. For example, several students have shown me such a copy in which "not equals" is replaced by "equals"!! Beware!
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. 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.

Organization of this Class

Homework will be assigned daily. Homework problems to be collected for grading will be indicated in red. 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 and will be counted in your final grade.

Every student's 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.
Attendance will be taken and recorded daily and unexcused absences will reduce your final average as follows. If UA is the number of your unexcused absences, UA/4 will be subtracted from your final average. 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.


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. Your final average will be your test average minus one fourth of the number of unexcused absences from class. 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.

Unhappy with your grades in Math?

Click here for a Six-Step Plan to improve your grades!


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. 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
January 9 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.
January 11 1.1 / 1, 5, 9, 11, 13, 15, 17, 19, 21, 37, 39.
January 14 1.2 / 1 -- 5, 11, 19, 26, 27, 29, 37, 47. 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.
January 16 1.2 / 28, 38. For #28, please give a reason for your answer.
January 18 1.3 / 1 -- 7, 13 -- 15, 17, 19, 22, 25, 29, 35, 59.
January 23 1.3 / 24, 30, 36. Also: 2.1 / 1--3, 5, 7--9 (odd), 15, 17, 19, 21.
January 25 Please hand in 2.1 / 4, 6, 44.
January 28 2.2 / 2, 3, 5--8, 10, 11, 13, 15, 19, 21. Do your best with these problems and we'll go over these carefully on Monday in class.
January 30 Please hand in 2.2 / 14, 16b. .
February 1 2.3 / 1 -- 13 (odd), 17, 19, 29, 33, 35, 37, 43, 47.
February 4 Please hand in 2.3 / 18, 44, 46 . Also: 2.4 / 21, 23, 55, 57, 59, 82, 83.
February 6 2.4 / 1 -- 11 (odd), 17, 29, 31, 35, 84, 86.
February 8 Please hand in 2.4 / 4, 32, 40.
February 11 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!
February 13 First Hour Test today.
February 15 3.1 / 1, 3, 5, 9, 15, 17, 19, 33, 35.
February 15 Please download and read carefully the Hour Test #1, Spring 2019, Solution Sketches and Class Statistics.
February 18 Please hand in 3.1 / 16, 18 .
February 20 3.2 / 1 -- 9, 11, 15, 17, 23, 27, 29, 37, 39.
February 22 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.
February 27 3.3 /1, 3, 5, 9, 13, 17, 21, 27, 29, 31, 33, 35 .
March 1 Please hand in 3.3 / 28, 30, 36. Also: 3.4 / 1, 3, 7, 9, 11, 13, 15, 17.
March 8 3.4 / 19, 21, 23, 31, 37, 41, 43.
March 11 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. Also: 4.1 / 1, 3, 5, 7, 9, 11, 17, 19, 21, 23, 25, 27.
March 13 Please hand in 4.1/ 20, 30. Also: Bring questions to review for the second hour test!
March 15 Hour Test #2. This test will cover all work assigned since the first hour test.
March 17 Please download and read carefully the Hour Test #2, Spring 2019, Solution Sketches and Class Statistics.
March 20 4.2 / 1, 3, 5, 7, 13, 15, 17, 19, 23, 25, 27, 45, 51, 59, 61.
March 21 No office hours this Thursday, March 21. Sorry.
March 22 4.2 / 10, 28, 52.
March 25 4.3 / 1, 3, 5, 7, 13, 21, 23, 25, 35, 41, 47.
March 27 4.3 / 8, 42.
March 29 -- April 1 5.1 / 1--3, 15, 25, 29; 5 -- 9(odd), 31, 41.
April 3 5.1 / 12, 16, 42.
April 5 5.2 / 34. Also: 5.2 / 1, 5, 9, 13, 33, 35.
April 8 6.1 / 1, 3, 5, 7, 9; 11, 13, 15, 17, 19, 21; 31, 33, 43, 44. Assume in these exercises that A is invertible if and only if det(A) is nonzero. We will prove this later.
April 10 6.1 / 18, 26. Also: 6.2 / 1--9, 11, 13, 15, 47, 51
April 12 6.2 / 16, 22. Also: 6.2 / 17 -- 21 (odd), 25, 43.
April 22 Third Hour Test today! This test will cover assignments that were due before today but since the second hour test.
April 23 Please download and read carefully the Hour Test #3, Spring 2019, Solution Sketches and Class Statistics.
April 26 Study very carefully everything you missed on the third hour test---especially the matrix of a linear transformation with respect to a given basis! Also: See below!
Bring questions to review for the Final Exam! Don't forget to review from the beginning of the course! Also, bring a number 2 pencil on the last day to fill out the end-of-course evaluation form!!
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.
April 29 Final Exam Week Office Hours:
Mon: 1--2:30
Tuesday April 30, 12:30- 2:30 PM The Final Exam will be Tuesday April 30, 12:30- 2:30 PM.
mAY 4 Please download and read carefully the Final Examination, Spring 2019, Solution Sketches and Class Statistics.