Syllabus and course information

Instructor : Dr. David Groisser

I receive a ton of email, so please be aware that:

• I won't answer math questions by email.
• I don't answer email that lacks an informative subject line and the sender's full name.
• I delete, without reading completely, any email that requires me to open an attachment whose nature or purpose I can't easily determine without opening.
• In general I answer students' emails only on days that I normally have office hours, and only at certain times. On office-hour days, I will generally respond to emails that arrive before the halfway mark of my office hour (or that arrived earlier, some time after my previous office-hour). For these emails, I will generally respond during my office hour if I have time left after I'm done seeing students, or after my office hour otherwise. Exception: I generally do not wait till the next office hour to respond to emails inquiring about (possible) typos in a homework assignment, or informing me of some problem with one of my course webpages.
• I never provide any grade information by email.

Office Hours: Tentatively Tuesday 6th period (12:50-1:40), Wednesday 9th period (4:05-4:55), and Friday 9th period (4:05-4:55). My office is Little Hall 308. Please come early in the period or let me know to expect you later; otherwise I may not stay in my office for the whole period. See my schedule for updates. Students who can't make scheduled office hours may see me by appointment on most weekdays (but never on a Thursday). If you have the flu or similar contagious disease, or think you might, please do not come to my office.

Textbook: Nagel, Saff, and Snider, Fundamentals of Differential Equations, 9th edition. If you would like to obtain access, at a discounted price, to the ebook-version and associated materials, please follow the instructions here. (I do not use Canvas.)

There will also be some required readings from notes by Dr. Groisser. These notes will be linked to the Miscellaneous Handouts page.

Prerequisite: MAC 2312 or equivalent. You will need a good working knowledge of Calculus 1 and 2 (as well as precalculus algebra and trigonometry). In particular, you will be expected to know integration techniques; the chain rule; partial fractions; and the algebra, calculus, and general properties of sines, cosines, and exponentials. If you are weak in any of these areas, or it's been a while since you took calculus, you will need to spend extra time reviewing or relearning that material. Mistakes in prerequisite material will be graded harshly on exams.

Knowledge of partial derivatives (usually covered in Calculus 3) is not a prerequisite but would be helpful. Syllabus (course content): This course is an introduction to ordinary differential equations (ODEs). ODEs enable a mathematical description of the laws of simple physics and virtually every science. We will cover chapters 1, 2, 4, and 6–8 of the textbook, with some omissions, and some material may be presented differently from the way it's presented in the book. Time permitting, we may cover some portions of chapter 3. Topics will include:

• concept of "ordinary differential equation" and meaning of "solution";

• statement and understanding of the fundamental existence/uniqueness theorem for solutions to initial-value problems;

• first-order methods (including separable, linear, and exact equations);

• some of the general theory of linear differential equations;

• second-order linear ODEs, with the constant-coefficient case treated in detail; method of undetermined coefficients; variation of parameters;

• higher-order linear ODEs, primarily the constant-coefficient case;

• method of Laplace transforms;

• power-series solutions of ODEs.

Exams. There will be three midterms (50-minute exams), each counting towards 20% of your final grade, and a cumulative final exam counting towards 40%. I reserve the right to adjust the percentages above in individual cases if I feel that circumstances warrant.

Tentative dates of the midterms are Sept. 17 (Mon.), Oct. 12 (Fri.), and Nov. 9 (Fri.). (The actual dates may be later than these tentative dates; they are unlikely to be any earlier.) I will always give you at least a week's notice before an exam. Do not, under any circumstances, use these tentative exam-dates as a guide to plan dates that you think you do not "need" to be in class, e.g. if you are thinking of being out of town on days that are not UF holidays. (See "Attendance Policy" and "What if you miss an exam?" below.) Expect a grade of 0 on an exam that you miss because you planned to be out of town on the date that the exam ends up being given.

The final exam will be given Monday Dec. 10, starting at 10:00 a.m., in our usual classroom. The date and time are set by the Registrar's Office; faculty members aren't permitted to change these.

Homework will be assigned daily and is due by the next class, but will not be collected. It is critical that you keep up with the homework daily. Far too much homework will be assigned for you to catch up after a several-day lapse, even if your past experience makes you think that you'll be able to do this. I cannot stress this strongly enough. Students who do not keep up with the homework frequently receive D's or worse (or drop the class to avoid receiving such a grade).

The assignments will be posted on the homework webpage. Assignments that are posted prior to class are estimates; they will often be modified within a few hours after class, according to how far we got that day. You are responsible for checking this page frequently (early enough for you to complete each assignment by its due-date), since in addition to updated assignments, other important information such as exam-dates will be confirmed on that page. Of course, changes of exam-dates will also be announced in class well in advance. However, if you are unaware of a changed exam-date because you were absent when the change was announced and you didn't check the homework page for several days, and this causes you to miss an exam or do poorly on it, that poor grade (0 if you miss the exam) will still be averaged into your final grade according to the percentages above.

On most days I will not answer homework questions in class; you should see me in office hours for questions about homework (or the material we're covering). But the class day before an exam will always be used for Q&A, and homework questions then are fine.

In general I advise against using solutions-manuals. To learn mathematics, you need to see a small number of problems worked out by someone else, just to see the principles illustrated; you need to do a large number of problems by yourself. The problems that I assign are selected to be doable based on what should be your accumulated store of knowledge and skills from your previous math classes, plus the material cover in class and in the textbook up to that point. In the long run, you will learn more by struggling with a problem unsuccessfully for two hours, than by giving up after a few minutes and looking at someone else's solution. Also, the solutions in solutions-manuals are sometimes wrong or inefficient.

I do not currently plan to use any online homework system. I have not seen any that I could trust not to count some right answers as wrong, or some wrong answers as right.

Attendance policy. Students are expected to attend every lecture, barring such things as illness, weddings, funerals, family emergencies, UF-sanctioned extracurricular activities, and religious holidays of which I am informed in advance (see "Religious Holidays" below). Students who choose (for other reasons) not to attend class regularly are forfeiting the right to my help in office hours, including explanations of their mistakes on homework and exams. These students should also not expect replies to their emails, even for questions like "Is there an exam tomorrow?" or "Have you decided when the next exam will be?" Also be aware that the University of Florida Attendance Policies contain the following paragraph:

The university recognizes the right of the individual professor to make attendance mandatory. After due warning, professors may prohibit further attendance and subsequently assign a failing grade for excessive absences.

A grade penalty of up to 5% may be imposed for an unexcused absence on the Monday before Thanksgiving.

I expect students to arrive on time and to pay attention for all 50 minutes of the period. Arriving late is disruptive (as is leaving early). If a non-optional time commitment (e.g. a class the previous period in a distant location) will force you to be late on a regular basis, let me know at the start of the semester. Students with a contagious illness are asked to exercise good judgment and to be considerate of their classmates and instructor when deciding whether to come to class. Coughing and sneezing in an enclosed space like a classroom or office is a wonderful way to spread germs.

Classroom decorum:

• As mentioned above, I expect you to pay attention for all 50 minutes of the period. Reading the newspaper, reading messages on your phone, looking at your computer, talking, texting, etc., are disruptive and rude.

• All sonic alerts from your electronic devices should be turned off. You may leave your phones in "vibrate" mode so that if UF sends an Emergency Alert, you will receive it. Note that in this case everybody's phone will be vibrating at the same time, so it will be obvious that something significant is happening. If your phone starts vibrating and nobody else's does, please ignore it. (If you ever need me to make an exception to this rule, e.g. because of a family medical emergency, let me know before class starts.)

• Please also avoid all other disruptive or distracting noises, such as the tapping of pencils or feet, or the zipping and unzipping of backpacks several minutes before the end of class.

Grading. The grades that UF currently allows instructors to assign are A, A–, B+, B, B–, C+, C, C–, D+, D, D–, and E. (For grade-point equivalencies of these grades, see this catalog page.) All of these are grades are possible in this class, except the D–.

In my philosophy (and that of my own college professors) of what a minus-grades means, a B–, for example, is not the lower end of the B range; it is slightly but strictly below the bottom of the B range, and means that your work falls a little short of "good". (Said another way: another professor whose estimation of how good your work was is the same as mine, but who regards B– as meaning "the low end of the `good' range", would not assign you a B–; he/she would assign you a C+.) This philosophy is consistent with the degree-requirements for most majors at UF: courses count towards your major only if you get a "flat" C or higher, because a C– means that your performance was less than satisfactory—not that it was barely satisfactory—and therefore that you did not satisfactorily complete the course. This philosophy is also consistent with UF's S-U grade option.

For similar reasons, I have never given the D– grade. "D" means "unsatisfactory but passing". I have always considered the next step down to be failing, which at UF is the E grade. (Because a C is usually needed for a course to count towards requirements for majors, minors, etc., an unfortunate number of faculty, advisors, and students have come to refer to every grade less than C as "failing". This is not the correct meaning of "failing grade", nor has it ever been; again see this catalog page.)

I don't have a predetermined grade curve or predetermined percentages for letter grades. I decide the grade scale for each exam and homework according to the philosophy "A = excellent, B = good, C = satisfactory, D = unsatisfactory but passing". At the end of the semester, I use the cutoffs from the exams and homework and to determine the final grade cutoffs on a 1000-point scale. For example if the cutoff for a B is 72% on the first hour exam, 69% on the second hour exam, 76% on the third hour exam, and 74% on the final, to get a B for the course you'd need .20 x (72%+69%+76%) + (.40 x 74%) = 73% of the total number of points in the course, i.e. 730/1000.

Since I don't determine the exam-grade cutoffs ahead of time, I can't tell you in advance exactly how many points you'll need to get a particular grade for the course. The grade-scale page for the last time I taught a non-honors section of MAP 2302 (Spring 2017) may give you a rough idea of what to expect. (I taught MAP 2302 in Spring 2018 as well, but that was an honors section, so the grading standards I used were somewhat more rigorous than what I use in a non-honors section.) You can find more examples of my past grade-scales by navigating from the "Past Classes" link on my home webpage. However, there is no guarantee that this semester's grade-cutoffs will be close to those of any particular past class of mine; they could be higher or lower. (There has been a great deal of variability in the strength of my students in the more than 30 times I have taught MAP 2302.)

Workload: On average, in order to receive an average grade, students should expect to spend eight to ten hours per week studying and doing homework for this class. This time-estimate is an average, not a maximum—some students will require more time, some less; some weeks the workload will be heavier, some lighter. Some circumstances that may increase your workload are:

• You did not study a similar amount in your previous calculus or precalculus classes.
• You have not retained the knowledge and skills that are the purpose of the prerequisites for this course.
• You cannot do algebra quickly and accurately without a calculator (this may be the case if you did not do a large number of exercises in your calculus or precalculus classes, or if you have relied heavily on calculators in the past).
• You want to get an A.

Additional Information

What if you miss an exam? If you miss an exam for a valid reason, and supply me with satisfactory documentation by your next day back in class, I will work out with you some way that is as fair as is feasible for you to make up the missing grade-component. Except in very large classes (which I don't teach) with cookie-cutter exams (which I don't give), there is no such thing as a fair make-up exam. Thus, the way I have you make up the missing grade-component may or may not be via an exam. If you miss an exam for a reason that I do not consider valid (consistent with UF policy on which absences should be excused), or do not supply me with satisfactory documentation by your next day back in class, you should expect to receive a zero for that exam. If extenuating circumstances cause a reasonable delay in your providing me with satisfactory documentation, I may treat your exam-absence as valid and documented. (However, I will be the sole judge of what is "satisfactory", "extenuating", and "reasonable".) If you are too ill to take an exam, please notify me by phone or email before the exam starts (if possible), even if it's just a few minutes before.

Student Honor Code. UF students are bound by The Honor Pledge, which states:

We, the members of the University of Florida community, pledge to hold ourselves and our peers to the highest standards of honor and integrity by abiding by the Honor Code. On all work submitted for credit by students at the University of Florida, the following pledge is either required or implied: "On my honor, I have neither given nor received unauthorized aid in doing this assignment."

The Honor Code (which can be found here) specifies a number of behaviors that are in violation of this code, and the possible sanctions. Furthermore, students are obligated to report to appropriate personnel any condition that facilitates academic misconduct. If you have any questions or concerns about student conduct, please consult your instructor.

Religious Holidays. The following is part of the University of Florida Policy on Religious Holidays. "Students, upon prior notification of their instructors, shall be excused from class or other scheduled academic activity to observe a religious holy day of their faith."

Tentative, approximate weekly schedule of lectures: Click here. You are expected to read the relevant material in the appropriate chapter-section of the textbook no later than the day after we cover that material in class. Preferably, do the reading earlier than that.

Accommodations for students with disabilities. Students requesting classroom accommodation must first register with the Dean of Students Office. The Dean of Students Office will provide documentation to the student who must then provide this documentation to the instructor when requesting accommodation.

Teaching-evaluations. Students are expected to provide feedback on the quality of instruction in this course based on 10 criteria. These evaluations are conducted online at https://evaluations.ufl.edu. Evaluations are typically open during the last two or three weeks of the semester, but students will be given specific times when they are open. Summary results of these assessments are available to students at https://evaluations.ufl.edu/results.

U Matter, We Care initiative: Your well-being is important to the University of Florida. The U Matter, We Care initiative is committed to creating a culture of care on our campus by encouraging members of our community to look out for one another and to reach out for help if a member of our community is in need. If you or a friend is in distress, please contact umatter@ufl.edu so that the U Matter, We Care Team can reach out to the student in distress. A nighttime and weekend crisis counselor is available by phone at 352-392-1575. The U Matter, We Care Team can help connect students to the many other helping resources available including, but not limited to, Victim Advocates, Housing staff, and the Counseling and Wellness Center. Please remember that asking for help is a sign of strength. In case of emergency, call 911.

Contact information for the Counseling and Wellness Center: http://www.counseling.ufl.edu/cwc/Default.aspx, 392-1575. For emergencies, call the University Police Department (392-1111) or 911.

Goal of course: For the student to master the course-content.

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