University of Massachusetts, Amherst
Math 471

Number Theory
Fall 2006

This is the homework page for Math 471. Here is a link back to the main page for Math 471.

Homework 1 (pdf) HW1 is due on Wednesday September 13.


Homework 2 (pdf) HW2 is due on Wednesday September 20. It is much longer that HW 1.


Homework 3 (pdf) HW3 is due on Monday October 3; THERE WILL BE NO EXTENSION FOR THIS HW. The assignment IS NOW COMPLETE.



Homework 1 solutions Homework 2 solutions Homework 3 solutions SAMPLE EXAM 1


Homework 4 (pdf) HW4 is due on Monday October 16; THERE WILL BE NO EXTENSION FOR THIS HW. YES THERE WILL! PROBLEM 4 was incomplete. HW 4 is now due Wed Oct 18. Note that Exam 1 is on October 16.

Homework 5 (pdf) HW5 is due on Wednesday Oct 25.

Homework 6 (pdf) HW6 is due on Monday Nov. 6. (CORRECTED ERROR IN PROBLEM 2(c) Monday noon).

Exam 2 SAMPLE

JUST OUT OF THE OVEN A Review Sheet of some of the facts you should know for Exam 2. It talks about Z/mZ not at all about primes and their distribution.

Solutions to HW 4,5,6 are now here. Homework 4 solutions Homework 5 solutions Homework 6 solutions

Homework 7 It was due Monday Dec. 4th in class, but I'm extending the deadline to Wed Dec. 6th in class. Problem 9 has a typo: it should read "ed = 1 mod phi(n)" not "ed = 1 mod n".

Homework 8 Due Wed Dec. 13th in class. On Friday December 8, I added more hints to file! On Sat. December 9, I corrected a typo in Problem 6 caught by Ashley.

Solutions to Exam 1 (except definitions)

Solutions to Exam 2 (except definitions)

Solutions to HW 7

The (Long-Awaited?) Final Exam Sample

If you're interested in earning 1 extra point for your final grade AND FOR THAT OF EVERY SINGLE STUDENT IN THE CLASS!, go to Mini-Me Project 1.



Homework 9 This is an extra homework you can start working on already: students who want to boost their homework grade should turn this one in, but it's not required! You can turn this in anytime before the start of the final exam. There was a minor typo in problem 4, now fixed.

Please Read the following carefully; it is very important to comply with the Rules discussed below.

General remarks (with thanks to Tom Braden): For many of you this will be one of your first mathematics class where concepts and proofs are more important than algorithmic computation.  Do not make the mistake of treating this like a calculus class!  You will need to be much more active in your learning.  In order to really understand the concepts, you should ask lots of questions like: What happens if I change this definition in some way? What goes wrong if I leave out an assumption from this theorem? Are there any other examples that work like this?  Is this like something I've already seen?  You should do this in class, while reading the book, and while working on homework problems.

The text for this class is on the accessible side for an abstract math course, but it will still has many more ideas per page than your average calculus book.  Don't be discouraged if you must read slowly, or read many passages more than once: that is what is expected.  I strongly encourage you to read the material for a lecture before you come to class.  Read actively -- when the book gives examples to illustrate an abstract definition, spend some time to convince yourself that they do in fact work, try to think of other examples of the same type, etc.

Doing plenty of examples is essential for attaining a solid understanding of any abstract theory.  We will do some examples in class, but it is not possible to do enough and still cover all the material.  The homework problems I will assign should only be taken as a starting place; there are lots of interesting problems of various levels of difficulty in the various texts, in the Extra Credit Problems I will assign.

Homework Rules and Guidelines: Why are you are attending a University instead of studying on your own? So that you can be part of an interacting academic community. So, when you get stuck, seek help from your instructor, other students, classmates ...! I especially recommend that you work with your fellow students in groups. If you are stuck on a problem and seek help from an instructor or a fellow student, you owe it to yourself to aim for an understanding of the concepts and ideas that come up in the discussion (do not just memorize the series of steps leading to the solution). Then, go home and reconstruct the argument for yourself in the privacy of your own brain, to make sure you are not merely reproducing mindlessly something you have not thought through. Remember that during tests and quizzes, you will have to rely on your own understanding of the material.

Here are the rules for collaborating on homework problems:

I. You must list the names of all people with whom you discussed each specific problem.
II. You MUST write your solutions completely independently.

Failure to comply with these rules may result in disciplinary action. Homework will be due on Thursday at the start of lecture, unless othewise stated. Late homework will not be accepted. Please note that the lowest homework grade will be dropped.