21-241 Matrix Algebra

Important: Do not make travel plans which require you to leave campus before 9 PM on Tuesday, Dec 16. Enrollment Services may schedule our Final Exam for as late as that evening. Hence you should make your travel plans under the assumption that you will have to be here, until you know for sure. If your parents will be making reservations for you, please keep them informed so that they do not make conflicting plans for you. No one will be permitted to take the Final Exam early.


The course will have three in-class exams and a comprehensive Final Exam. The in-class exams will be given during the regular lecture hour on September 22 (Monday), October 24 (Friday) and November 24 (Wednesday).

Tests will be closed-book and closed-notes. No calculators will be permitted. In case you must miss an exam due to illness, family emergency, University-sponsored trip, or religious observance, please notify me as soon as possible (email is good). I may require documentation in order to excuse the absence, and then we can arrange for you to make up the exam.


There will be twelve homework assignments. If you turn in every assignment and have a score of at least 60% on each one, you will earn a HOMEWORK BONUS in the form of 3 points tacked on to your overall final average. (See below.)

Homework will be scored according to three criteria: (i) evidence of conscientious effort on your part to work all problems completely and correctly, (ii) the clarity of the work, and (iii) the correctness of the work. Regarding point (ii), you should resist the urge to simply write endless strings of computations with no explanation of the thought process behind your work. Include transitional phrases and explanations such as, "Now we must find the eigenvalues of this matrix." The habit of sprinkling sentences through your write-up will carry over to exams, which is very important, because when we grade exams, the only way we can tell what was going on in your mind is by looking at what you've put on the paper. So use the homework as practice for writing up very clear work.

Collaborative effort on homework is strongly encouraged, because (i) the chance for you to articulate mathematical ideas to your peers (as you help them with problems) is effective in concretizing your understanding of the concepts, and (ii) you are likely to benefit from the insights of your peers, who may reveal connections that you had not made. However, each student should individually write up his or her own work, and you should never give your pals access to the final version of your homework write-up. In cases where two or more homework papers are clearly the work of one mind, the score due will be split equally among those involved.

Officially, late homework is not accepted, but if you feel that your situation is exceptional, you must personally bring the matter to me. I only accept late homework with a face-to-face explanation, or you can email me in advance of the assignment being due, to request an extension.

If you hand in all homework assignments and score at least 60/100 on each one, you will earn the Homework Bonus (see below).

It is recommended that you save all returned homework and exam papers until you have actually seen your final grade for 21-241. Occasionally errors occur and a homework score does not get recorded. (Perhaps your paper gets "stuck" to the one above it as I am, or a grader is, processing a stack of papers.) In case a discrepancy results, the matter is more easily rectified when you can produce the returned paper as evidence.

Grading Questions

Questions regarding the grading of exams or of homework must be brought to me at my office, outside of class. No such issues will be addressed in the lecture room. If you have a question or concern, please come during office hours or email me to make an appointment.

Letter Grades

Your final grade will be determined by your Adjusted Final Average (AFA), as follows:
                     AFA           Grade
                    90-100           A
                   80-89.999         B
                   70-79.999         C
                   60-69.999         D
                   0-59.999          R

Your AFA is equal to your Unadjusted Final Average (UFA), plus three points if you earn the HOMEWORK BONUS. Otherwise, AFA = UFA. Your UFA will be determined by whichever scheme below is more favorable to you:
        Method A                  Method B
        --------                  --------

      Exam 1  18%               Exam 1  15%
      Exam 2  18%               Exam 2  15%
      Exam 3  18%               Exam 3  15%
      Final   36%               Final   25%
      HW      10%               HW      30%