Values of
Sine and Cosine at Standard Angles
-- All students are strongly advised to know the values of the six trig
functions at the standard angles (all multiples of pi/4 and pi/6); this
short commentary and the linked diagram will help you both remember
these values, and understand the fundamental relationship between
trigonometry and the unit circle.
The Remainder Theorem and the Factor
Theorem
-- These are fundamental facts about polynomial algebra, and they are
simply stated and easy to prove; but for some reason they are not
covered in most high school curricula any more. I strongly
encourage students to look at this brief description and ensure an
understanding of these theorems and their proofs.
Some
comments about Single Variable
Integrals
-- This is a document that I wrote in the Fall of
2004
after teaching the Math 103 section about integrals of parametric
functions. When we get to the integrals portion of this course,
the first part of this could be useful to you.
My other
Course Websites
-- Students can find here all of the websites for every course I have
ever taught.
Java
Applets --
This is a site that was created by a colleague at Stanford; several of
the tools there could be useful to you for visualizing multivariable
functions.
Exam Solutions
2008-2009 Fall:
Exam 1Exam 1 SolutionsExam 2Exam 2 Solutions2007-2008 Spring:
Exam 1
Exam 1 Solutions
Exam 2
Exam 2 Solutions
Exam 3Exam 3 Solutions
2007-2008 Fall:
Exam 1
Exam 1 Solutions
Exam 2
Exam 2 Solutions (Note, there is a computational error in the bottom left element of the solution matrix in #2a.)
Exam 3
Exam 3 Solutions
2006-07 Spring:
Exam 1
Exam 2
Exam 3
Exam 1 Solutions
Exam 2 Solutions (Note, there are computational errors in the solution to problem 1a)
Exam 3 Solutions (Note, there is an arithmetic error on number 5; the answer should be 11, not 7.)
Homework
Homework problems are assigned for every lecture, and students should
ideally complete each assignment on the day of the lecture.
The
assigned problems for each lesson will be listed on the syllabus.
(Note, we might find ourselves behind or ahead of the posted
schedule; if so, you should do the problems as we actually finish the
sections.)
Make sure you staple your homeworks! We cannot give credit to
students
for work that was lost as a result of not being stapled.
Also,
make
sure to put at the top of the front page your name, and the section
number(s) for those problems.
In order to give flexibility to students, the assignments for the
previous three lectures will be picked up in section every Tuesday, and will be graded and returned as soon as
possible.
No late homework will be accepted without the
Short
Term
Illness Notification.
In calculating homework grades, the lowest of your homework scores will
be dropped. The purpose of this policy is to handle
exceptional
circumstances.
Please do
not request to have late
homework accepted without filling out the Short
Term
Illness Notification.
Also, it is inadvisable to skip a homework
unless absolutely necessary, since only one homework will be dropped.
Working together in groups on homeworks is
strongly encouraged!
You will find that the people you are working with either (1)
understand something you don't, in which case they can explain it to
you; (2) understand something that you do understand, but from a
different point of view -- these additional perspectives can prove to
be very useful; or (3), don't understand something that you do
understand -- in which case you have the opportunity to explain it to
them... I think you will find that in the process of
explaining
something, very often you will achieve a better understanding yourself.
Of course, it goes without saying that even though you may
work in
groups, the homeworks you turn in must be your own work.
You may
share ideas, perspectives, approaches to problems, but copying is not
allowed. Furthermore, keep in mind that the homeworks are
primarily a learning tool, and count for a fairly low percentage of
your grade. Do not deprive yourself of this invaluable
learning
opportunity!
Here is the procedure we will use this semester for regrades:
(1) Write a clear and complete
description of why you feel your paper deserves more points than you
originally received.
(2) Attach that description to your homework paper.
(3) Put that paper into the pile in the following section, when your TA is collecting the next week's homework.
(4) The grader will receive your note and original
paper, will give it fair consideration, will consult with me or your TA
if
necessary, and then will make a change to the score if that is deemed
appropriate. He will then also make the change on the homework
gradesheet.
(5) The grader will put the paper back in the pile
and it will be returned to you along with those other homeworks.
Here are a few thoughts to keep in mind about
regrades:
(a) It is entirely possible and reasonable that the grader might have
misread your paper, and with your explanation realize that you do
indeed deserve more points. In such a case, he will be very happy to
award more points.
(b) It is also very common for a student to feel simply that too many
points were taken off for a given error. In these cases, the student
should be prepared for the likely conclusion that no additional points
will be awarded. The point here is that this is a subjective
situation, and a choice has to be made. The grader makes the decision
based on his feeling about the importance of a given aspect of the
problem, and the grader's opinion on this question is the standard.
Common examples of these types of disagreements involve the amount of
explanation that should be given, and the relative importance of
different parts of the problem. These are highly subjective questions,
and reasonable people will come to different conclusions.
Remember that this is a curved class. So,
when it
comes to questions about too many or too few points being taken off, it
is far
more important that the grader's scheme be applied consistently across
the board for all students
than that it be something other people might or might not agree with.
(c) When you submit your paper for a
regrade, the grader might possibly come to the conclusion that too many
points were awarded in the first place. In such a circumstance, your
score could go down. Of course the grader will always make such
decisions dispassionately and fairly, but certainly you should only
submit for a regrade in a situation where you feel you have a
comfortably strong claim.
(d) The grader is a very reasonable and intelligent person, and
absolutely deserving of being addressed politely and treated with
respect. Make sure to phrase your requests calmly and reasonably. And
of course, always be prepared for the possibility that the grader might
have a different point of view than you on a given question, and that
his fair and reasonable consideration of your request might yield no
additional credit.
Grading
and
Exams
Final grades for the class will be determined by the total number of
points earned in the class. These points are given based on
performance on the items below, with the following maximum possible
scores:
Homework average: 50 possible points (the lowest
homework
score is dropped)
Tests:
300 possible points
(3 exams x 100 points each)
Final Exam:
200 possible points
------------------------------------------------------------------------------------------------
Total:
550 possible
points
The student should be prepared for the fact that the grading system for
these exams is NOT the same as the one most students became accustomed
to in high school. There are two main properties in particular of the
high school system that will not be used in this class :
1) In most high school grading systems, there are fixed, arbitrary
numbers that determine the cutoffs between different letter grades --
these cutoffs were invariant, and independent of the exam. The problem
with this that it forces the instructor to create exams that are always
the same difficulty; in other words, the instructor must make sure that
all exams will yield the same mean score. Furthermore, it requires that
the distribution of scores also be roughly constant. Achieving both of
these goals is not only difficult, but impossible to perform perfectly.
This system ties the instructor's hands severely, and is totally
unnecessary! Of course it is important that final letter grades for a
class follow a prescribed plan, so that those letter grades have some
meaning outside of the context of that class. Ensuring that is actually
easier if the instructor chooses the cutoff numbers after having seen
the distribution of student scores. The cutoffs can then be chosen
while incorporating important considerations such as the difficulty of
the exam, or any other points about the exam that may be relevant.
2) The class average on exams in most high schools was usually
expected to be somewhere in the mid-eighties. While this is reasonable
considering the nature of high school, it is not always appropriate for
a college setting.
In this class, certainly, there are expectations for the student
that are much more demanding than those of most high schools. We expect
that the student will achieve much more than the mere ability to
reproduce what he or she has seen in class. In particular, we expect
that the student will achieve an understanding of the ideas that are at
the foundation of the methods -- and thereby gain the ability to apply
those ideas to situations that he or she has not already been exposed
to.
Since the expectations of this class are more difficult than those
of high school, it stands to reason that the exams, designed to test
the students mastery of these more lofty goals, must involve more
difficult questions; and therefore, the exams must be more difficult.
Clearly this will result in class averages that are lower than what one
would expect if the exams were more like those of high school. It will
also tend to result in score distributions that are more broad, since
the students responses can be expected to be more varied.
The student should be fully aware of these points before taking an exam
in this class.
It is very dangerous to associate letter grades with performances on
individual exams, because it is very difficult to predict how the
distributions for those exams will interact when the total score
distribution is formed. Therefore, the class will usually be informed
only of the class median and mean for a given exam -- letter grades
will not be assigned.
I will periodically distribute a list of all student total scores in
the class (with names removed), so that students can see exactly how
their own total scores compare to the rest of the class.
Calculators
We will not be using calculators in any aspect of this
course.
You may use a calculator on a homework problem if you feel that it will
help you understand the concepts, but you may not make any reference to
the use of a calculator on the homework you turn in, except in the case
of a problem that requires substantial and nontrivial arithmetic.
Calculators will NOT be allowed on the final exam or on the in-class
exams. I
also generally discourage their use on the homeworks, since students
may develop a dependence that will hurt them on the exams.
You are encouraged though to take advantage of the online resources
linked to from this page, including the Java Applets (there are many
tools there that can help you visualize and develop a geometric
intuition for some of the ideas in this course).
Getting
help
There are several resources that students should be aware of; make sure
to read the
Sources
of Help for First-Year Students.
I'd also like to emphasize that classmates can be an excellent resource
as well. I refer you above to my comments on this in the
homework
section.
Be sure to realize that you are encouraged to use these resources for
more than just help on the homework... Ask questions about
general ideas you are having trouble with, specific parts of the
lectures that you did not understand... Of course you should
also
seek help with homework if you find yourself stuck on a problem for an
extended period of time.
Duke Community Standard
The
Duke Community Standard is taken very seriously on Duke campus, and you are all
reminded to make certain you are familiar with it.
In this course some collaboration is allowed and encouraged, but of
course your work must all be your own. Here are some specific
comments about the graded items in this class:
Homeworks -- You are encouraged to work in groups to exchange ideas and
help each other understand how to approach problems, but the student's
work must be his or her own. Copying and dictating are not
allowed.
Exams and Quizzes -- Students are not allowed to have any outside help
during exams or quizzes.
Attendance
Attendance at all lectures and sections is required . If you miss a
lecture, it is your responsibility to catch up on the
topics that you missed. You should keep in mind that in this course,
the material builds on itself; if you miss some of the material,
subsequent lectures will seem much more difficult to you.
Absences from exams will be excused only for reasons such
as serious illness or appropriate official university
activities.
In either case, a written notification from the dean is
required.
In the case of illness, this must be done with the
Short-term
Illness Notification form. In the case that an
absence from
an exam is excused, the grade will be determined based on your
performance on the final exam for the course, and relative to the
performance of the rest of the class on that exam.
Students should note that use of the Short-term Illness Notification
form is subject to the Duke Community Standard, discussed and linked
above. In particular, it is expected every student will take
reasonable responsibility for his/her own health at least to the extent
that such health is needed to be able to participate in
classes.
Here are some examples:
-- If on the day of an exam in this course you have a debilitating
headache caused by a virus, then it would be appropriate to use the
short term illness form. However, if you have a debilitating
headache caused by a hangover, it would not be appropriate to use the
short term illness form.
-- If on the day of an exam in this course you have a severe cold
caught two days earlier while camping outside for basketball tickets,
then it would be appropriate to use the
short term illness form. However, if you have had the cold
for
two weeks and are still camping outside for basketball tickets, it
would not be appropriate to use the short term
illness form.
Additional Comments
As
was discussed in the section on Grading and Exams, the goals of this
course are higher than those of high school math courses, and even
higher than most single variable calculus courses. Specifically,
students in this course will be expected not only to be able to perform
computations, but also to be able to demonstrate comprehension of the
ideas behind those computations.
We expect students to
demonstrate this comprehension by showing the process used to perform
the computation, with sufficient commentary to allow the reader to
conclude the thought process the student was using in working that
problem.
The correct numerical answer does not guarantee that
the student will get full or even majority credit for the problem.
Rather, students will be graded on the validity of the method of
computation, the extent to which the computation and commentary
demonstrate the student understands the underlying ideas, and the
clarity of those explanations.
It is very likely that this
system of evaluation is very different from the ones the students might
have become accustomed to in high school.
To a great extent, this is a writing class.
This
might sounds like an outrageous statement, but the fundamental point
here is that this course, just like a history course or a political
science course, is about the comprehension and communication of ideas.
Obviously the types of ideas in question are different, but like many
or even most other courses on a college campus, this course requires
students to understand concepts, and then to communicate that
understanding through writing. In this course the writing comes in the
form of the answers that the student gives to homework and exam
problems, rather than essays.
Students should take very
seriously the idea that the solutions they write for the homework and
the exam problems should reflect this perspective. All too often
students think of the writing they do on an exam to be simply a
personal convenience for them -- that is, a tool to keep them from
having to work the problem entirely in their heads. This is NOT the
right attitude, and it will not lead to the desired credit on the exam.
Instead,
think of your writing on homework and exam problems as being
documentation of your thought process. You are communicating to
another person, namely the grader, and your goal is to communicate that
you understand the tools needed to solve the given problem and that you
know how to implement those tools. Of course in communicating that to
the grader, you will also write down the necessary algebra to allow you
to arrive at the final answer.
Write neatly!
The
all-too-common attitude in high school mathematics courses is that the
answer is the only thing that matters; if the grader can read the
answer, then the clarity of the rest of the work is not relevant.
As
per the above comments, this is not the case in this course.
Everything that is written on the exam is going to be read and
considered for the contribution it makes to demonstrating comprehension
of the ideas. So it must all be legible.
The same standards of
neatness and legibility appropriate to, say, a history class should be
applied in this mathematics class. Because of the types of notation
used we do not expect that the student will type the solutions to
homework problems; but, we expect that the solutions will be written
neatly and legibly, the papers should not be crumpled or stained, and
there should not be large areas of the paper scratched out. (If you
are not sure how to work a problem and if you are going to put its
solution on the same page as that of another problem, you should do
your scratch work on another piece of paper, and then write out the
solution neatly on the paper you will turn in.)
Furthermore,
note that the flow of ideas over the page should be reasonable.
Ideally, it should be "top down", or perhaps two or three column if
the student prefers. Either way, the grader should be able to look at
the page and effortlessly identify the location of the beginning of the
argument, and easily follow each successive step until arriving at the
conclusion.
Note, explanations that bounce around the page in a
seemingly random pattern will be more difficult for the grader to
follow, which invariably leaves the grader finding less clarity. This
can lead to the awarding of fewer points.
Sometimes there might be material that is fair game for an exam, but
for which the homework problems are not due until after the exam due to
the way the schedule and due dates are set up. Make sure to
consider this possibility when you are studying for the exam, and if
this should be the case you are strongly encouraged to do the
corresponding homework exercises before the exam in question, so that
you can get the needed practice for the exam.
There are many resources available to students in this class, and we expect students to avail themselves of all of them.
- Yourself
-- By this I mean that you are ultimately the one responsible for
ensuring that you learn the material. You cannot wait for help to
come to you, but rather you must seek it out independently and
aggressively. You must make sure that you are learning the
material to a sufficiently deep level, and you must be responsible for
finding the ways to improve your understanding if you are not certain
that your understanding is sufficient. Think creatively about the
different ways that you can learn!
- Book/notes -- I
strongly recommend that you read the appropriate sections in the book
before class! Of course with a first reading it is not expected
that you will understand everything, but a rough idea of what the topic
is and how the problems will be approached is extremely valuable when
you come to lecture; it will allow you to spend more time thinking
about the higher level ideas that we discuss there, and to minimize the
distractions of thinking about where things are going, and tedious
minutia that you could have picked up by reading.
I also
strongly recommend reading the appropriate sections of the book after
class! This will allow you to solidify the things you learned in
class.
Note also that in class, we will NOT cover all of the
material in the book for which you are responsible. There are far
too many things in this course to be able to spend sufficient class
time on all of them. So, in class I will discuss the ideas that I
think are the most important, and also the ideas that I think are most
difficult to get from the book. I will also do as many examples
as time permits, but the priority must be on the concepts.
- Instructor
-- Of course this is a given, but the point here is that you must come
to class in order to get any use from me as the instructor. It is
a tragic error to skip classes, thinking that your time is better spent
doing other things. You simply never know what will come up in
class, and if you miss the presentation of an idea that you are not
familiar with, it will be very difficult to make up for that loss.
Note,
in this course and most other math courses at Duke, the level at which
the material is presented is dramatically higher than that in even the
strongest high schools. It is at that higher level that you will
be tested... So, while you may have done very well in your
calculus courses in high school (note, almost every student in this
class has already had a course in calculus in high school!), that is no
guarantee that you will do well in this course.
- Help
Room -- The help room, linked above, is a wonderful opportunity for
students in this class to get assistance at a broad variety of times.
If you are having trouble with a particular problem then of
course you are welcome to ask for help there. But, more
importantly, this is also a time when you can get help with concepts
you are having trouble with. Go in with broad questions, like,
"I'm having trouble with problems that involve work," or "How can I
improve in making good guesses on substitutions to use for computing
antiderivatives?" The people in the help room should be able to
help you.
- Classmates -- As we discussed already in the
homework section, you are encouraged to work in groups on the homework,
to share ideas and exchange assistance on problems you are having
trouble with. In general I think that your classmates can be very
useful resources for you. Again, don't limit your use of this
resource merely to specific problems. Try to initiate broad
conversations on topics you are not sure about, and share your
different points of view. If you find that neither you nor any of
your classmates understands a particular point, then seek out help
either from the Help Room, or from me.
As previously discussed, the expectations in this class are very high.
- Memorization/Execution
-- Students in this course were almost certainly made very familiar in
high school with the idea that they should be able to remember needed
formulas and techniques, and work a problem out to its conclusion.
That is, that they should be able to execute skills that are
discussed in class. Students in this class are generally very
good at this sort of thing, because of that familiarity and the
predominance of that in high school classes.
However, because
most high schools emphasize ONLY this skill, many students in this
class expect that this is the only expectation that will be made of
them. This is most certainly NOT the case.
- Understanding
-- Very often a student can be sufficiently familiar with an algorithm
that he or she can execute the algorithm, and manipulate symbols in a
way that yields an answer; but still this student mightnot understand
either why the algorithm works, or the meaning and interpretation
behind each individual step in the algorithm.
Students
in this course will be expected to move beyond this level. That
is, they will be expected to understand what is really happening with
the algorithm, when it can be applied and why, and all of the
appropriate interpretations.
Problems will be constructed for
the exams that will test these sorts of understanding. Students
will also be expected to demonstrate such understanding by their
written annotations and explanations of their work on their exam
papers. Solutions that do not have sufficient or communicative
explanations will not receive full credit, even if the final numerical
answer is correct.
- Creative Application -- If a student
truly understands the tools that we discuss and how and why they work,
then he or she should be able to apply those tools and ideas to new
situations. That is, students should be able to use those tools
TO SOLVE TYPES OF PROBLEMS THAT THEY HAVE NOT SEEN BEFORE, EITHER IN
CLASS, THE BOOK, OR THE HOMEWORK.
This will seem
difficult at first, as students adjust to the needed higher level of
understanding that they must demand of themselves in this course.
But with sufficient practice, students will become comfortable
with this level of expectation.
To prepare for these
sorts of problems, students can pick a particular idea or tool from the
course, and then try to think themselves of a new sort of problem or
circumstance in which the tool might apply. Then the student
should work out those details.
Of course students can also look at all of the exams I have given in previous semesters in this course.
Students in this course will need to "raise the bar" on their personal
expectations on understanding, in order to do well in this course.
Note,
understanding is not a binary thing. That is, it is not the case
that someone either understands something, or they don't. Rather,
there is a continuous spectrum of comprehension, and study continuously
increases the level at which someone understands an idea. (One
might compare this scale to those for skills in a sport, say,
basketball -- certainly one cannot say that a player either does or
does not have a certain skill in the game; but rather, for each skill,
there is a continuous spectrum of levels of ability.)
In high
school, there is a "bar" that is implicitly set on this spectrum by the
types and difficulties of the problems that students are expected there
to be able to solve. This bar is set at a level that, while it
might be appropriate in a high school setting, is much lower than is
appropriate at Duke.
This presents a kind of psychological
challenge to students in this course. That is, students must find
a way to motivate themselves to understand things at a level higher
than they are familiar with, and furthermore they must then also find
ways to gauge their understanding.
This is a difficult task, but one that every student here must undertake.
I recommend the following exercise to help gauge your understanding on any particular topic. That is, ask yourself,
"Am
I prepared to give a 15-minute presentation to a group of other
students explaining what the big idea is here, how it works, why it
works, and then to answer questions from the group?"
This
hypothetical question has two things going for it. First, note
that the question forces a student to consider his or her ability to
communicate on a particular topic. My experience has been that in
order to communicate effectively on a topic, the most fundamental
requirement is a clear and comfortable understanding of the topic in
question. Furthermore, the process of preparing to communicate on
a given topic forces the mind to organize the ideas in a way that helps
understanding.
Second, public speaking is something that most
people are naturally apprehensive about. Often this apprehension
is based in some sort of fear of the possibility that one might be
exposed for not understanding something. By considering
a public speaking scenario, the possible resulting feelings of
apprehension might be a clue that you do not actually understand things
as well as you might have thought.
Note, some students take this
to an even higher level by actually giving such presentations,
in groups that they form themselves. I think that this is a
wonderful idea, and both presenting and listening can be useful
learning tools for participating students in such groups.