Math 44
Fall 2009 Home Page
Green Sheet


Class 20, Tue., Dec. 1, 2009
We heard/saw projects. Thursday's class is for review, bring questions!

Class 19, Tue., Nov. 24, 2009
We went over several handouts - please finish the handout on "web" diagrams and chaos.
Projects are due Tuesday. Projects should include a written report (600 words), one report per project. In the report you must describe - in detail - what each participant did, what course mathematics was involved and how it was used, what steps you took to create the project, and must include any references. Refer to the final project form for more information about the projects.

Class 18, Thu., Nov. 19, 2009
Here is the link to the Math 44 google group.
You are all members already under the email address which I have for you. But you must still register with Google. Go to the group site and they will ask you to register, if you have not already. Please use it to work on the take-home exam.

We did a "body" symmetry activity in which we constructed the table of "compositions" of four planar symmetries:
T for Translation (or slide),
G for Glide (also called glide reflection),
M for Mirror (or reflection), and
R for Rotation (180 degree turn).
Here's the table we constructed:

T
G
M
R
T
T
G
M
R
G
G
T
R
M
M
M
R
T
G
R
R
M
G
T

We also worked on the take-home exam, and did a fractal dimension handout.

Class 17, Tue., Nov. 17, 2009
We went over fractal dimension and some polyhedra calculations.
If you did not turn in your project form Tuesday, you MUST turn it in Thursday. If I returned it to you for corrections, please make them and turn in again on Thursday.
Do homework through section 6.5.
Turn in chapter 5 homework on Thursday.

Class 16, Th., Nov. 12, 2009
We went over more material on fractals.
We also worked on final projects. Please turn in your final project form, on Tuesday.
I emailed your take-home exam to your email address. Let me know if you did not receive it.
Complete section 6.4 homework.

Class 15, Tue., Nov. 10, 2009
We went over material on fractals and cellular automata.
Please complete handouts given out in class and bring back to class.
We also began talking about complex numbers.
Do homework for sections 6.3 and begin homework from section 6.4.
Here is your final project form, for the project which is due the last week of class. Fill out the form and turn in Tuesday.

Class 14, Thu., Nov. 5, 2009
We heard reports, saw more of the Martin Gardner video, and began chapter 6.
Do homework for sections 6.1 and 6.2.

Class 13, Tue., Nov. 3, 2009
We went over graph theory material.
Your papers are due on Thursday; be prepared to give a short oral summary of what you reported on.

Class 12, Thu., Oct. 29
W worked on the Poinsot Stars handout, due Tuesday.
We also saw some video of the Gathering For Gardner, learned how to tie a knot without letting go of the ends, and made some human knots. Please do the rest of the homework from section 5.4.
Your papers are due next Thursday, Nov. 5, see below.

Class 11, Tue., Oct. 27, 2009
We went over the modular arithmetic handout. Complete the Poinsot Stars handout and turn in Thursday.
We experimented with paper Mobious strips.
We also began section 5.3 on graph theory. Do homework for section 5.3.

Class 10, Thu., Oct. 22, 2009
We went over Patterns and Modular Arithmetic, which is to be turned in on Tuesday.
Bring the Poinsot Stars handout on Tuesday, we will start that as well.
We also built many polyhedra, and just began chapter 5. Please begin the problems for sections 5.1 and 5.2.
I will take up Chapter 2 homework on Tuesday, which is long over due! I will also take up chapter 4 homework next Thursday (we did not cover all sections of chapter 4).
Your pentomino tiling, with symmetries identified, is due on Tuesday also.
Use this handout showing you how to find the symmetries in your tiling to understand how to complete it.

Your next paper is due Thursday, Nov. 5. For your next written report, you are to report on a mathematical subject connected to this course, that has caught your interest. I suggest that you read a chapter or two from one of Martin Gardner's books on mathematics, he covers a wide variety of topics. Here is a list of a few of the 70 books by Martin Gardner.  Choose a chapter (or two) that is of interest to you and report on it:
The Colossal Book of Mathematics
Mathematical Circus
Mathematical Magic Show
The Magic Numbers of Dr. Matrix
Mathematical Carnival
Knotted Doughnuts and Other Mathematical Entertainments
Wheels, Life, and other Mathematical Amusements
Time Travel and Other Mathematical Bewilderments

You might also want to look at books by Ian Stewart, Keith Devlin, or Ivars Peterson.

Please check out one of the books and sign up to do a report on one chapter. You can email me which chapter you want to do a report on, if you have any question. This will be a 600 word paper, as before. The main criteria for how you select which chapter to report on is that it should be of interest to you. You will also give a brief 2-3 minute oral report on what you learned to the class, if we have time, on Th., Nov. 6.

Class 9, Tue., Oct. 20, 2009
We heard the mathematician biography reports. Here is an article published in yesterday's New York Times about Martin Gardner, in honor of his 95th birthday.
We also learned a little more about polyhedra. Please do the homework problems in section 4.5.
Also, prepare to turn in the pentomino tiling. You should show the symmetries in your tiling. Use this handout showing you how to find the symmetries in your tiling!

Class 8, Thu., Oct. 15, 2009
We went over symmetry handouts. Please complete
Rotational symmetry handout.
4-Fold rotational symmetry handout.
and turn in on Tuesday.
Your mathematician bio is due on Tuesday. Here is the list showing who is assigned which bio.

The reference books, Mathematical People and More Mathematical People is on reserve in the campus library. The report will be 600 words, and will also involve a short 2 to 3 minute oral report. Include in your paper some response by yourself to the person - is this someone you might like to have a conversation with, or is it someone who does not seem very interesting to you? Your main reference must be a printed source, not a web site, and you must cite any sources you use.

Please visit Scott Kim's homepage and look at the many examples of Inversions, some from his book by the same name, some animated. Recently other artists have produced these letterform images that exhibit symmetry, for example here is a site for ambigram tattoos by Mark Palmer. The artist John Langdon has also been creating Ambigrams for many years, and produced those used by Dan Brown in his book Angels and Demons. See Langdon's site for examples of his work, or look for his book Wordplay. Here's a site by the mathematician and artist Burkard Polster with lots of playful examples.

Symmetry leads us to the field of "tilings" or "tessellations." There is an enormous amount of recent mathematics and art  on this subject. Take a look at David Eppstein's enormous collection of links on tilings. He calls his collection of such links the Geometry Junkyard; it's very entertaining, in a mathematical and arts sort of way!

Here's a simple example of how the RSA code works.

You have an assignment to choose a pentomino and use it to create a tiling of the plane, then find the symmetries in your tiling.
You might also color the tiling in an interesting way! Indicate on the tiling exactly where the symmetries are. Here's a handout showing you how to find the symmetries in your tiling! Here are hundreds of links to some amazing tiling sites. Pentominoes each have five identical unit squares, linked complete edge to edge. For example, we might try to solve the same problem for the "hexomino:" there are 34 hexominoes, each having six squares. Here is a diagram indicating briefly how all 34 hexominoes tile the plane. These are not shown in complete detail; your penomino tiling should extend further than these, and indicate how the pattern you found really could extend in all directions throughout the plane.

Class 7, Tue., Oct. 13, 2009
We went over material on symmetry and you took some handouts home - please complete them and bring back to class. For those not in class print out and bring to class:
Rotational symmetry handout.
4-Fold rotational symmetry handout.

Please visit Scott Kim's homepage and look at the many examples of inversions.
Bring the Poinsot Stars handout, we'll do some work on it in class.
Here's a simple example of how the RSA code works.

Here's a list of "distributed" mathematical projects now being conducted throughout the internet.
Here's the "World Community Grid" site listing many online projects in which you (and your computer) can participate!
Here's another site for "Volunteer Computer Grids."

Here's an online article by Ivars Peterson on drivers license codes.
Here's Joseph Gallian's site on check digits in codes.

Read sections 4.3 And 4.4 and begin homework from those sections.

Class 6, Thu., Oct. 8, 2009
We  went over sections 4.1 and 4.2. Please do homework for these sections. Sorry this update is late.

Class 5, Tue., Oct. 6, 2009
We have first exam on Thursday.
We went over commercial codes that use modular arithmetic, and some homework about prime numbers.
Here is the list of mathematician bios, showing who is assigned to whom. Due Tuesday, Oct. 20.
Work on homework from chapter 2.5 also.

Class 4, Thu., Oct. 1, 2009
We went over Fibonacci numbers, and explored a pattern demonstrating that the sum of the squares of two consecutive Fibonacci numbers is another Fibonacci number. We completed and turned in the Modular Arithmetic Intro handout.

We also looked at prime numbers. Here is a 2 minute slightly nutty but mathematically accurate music video (professionally produced by Nova) of SJSU's Dan Goldston's discoveries about the Twin Prime Conjecture.

Here are some links to Fibonacci sites, it is required that you (at least) take a look at them. The second and third have lots of pictures!
A great site about Fibonacci numbers.
Here's another Fibonacci site with lots of pictures and interactive applets.
Here's an interactive site that helps explain phyllotaxis, which is the pattern of spirals in many plants. Within the site is a short film clip that is part of the explanation as to why the Fibonacci numbers appear in plants.

Here is a study guide for the first exam (next Thursday) from a previous quarter. We haven't covered all topics yet, and we've covered some that are not here, but this will give you a start. First exam is individual, open book, open notes, calculator but not computer allowed.

Here is a list of the contemporary mathematicians you will report on Oct. 20. Everyone will be assigned one mathematician on Tuesday, so you might want to look up some info on them first.

Homework:
Work problems in section 2.3 and 2.4. Section 2.4 is about modular arithmetic, which we've already studied, and its application to codes. The list of homework problems is at the bottom of this page.
Here is the  Fibonacci number assignment, turn in Tuesday as a "quiz." The first half of the quiz was your participation in counting the number of spirals in the pine cones; everyone in class received full credit. Make sure that the plant you choose exhibits spiral patterns, not just one of the Fibonacci numbers.
Please print out this handout, and bring them to class on Tuesday: Patterns and Modular Arithmetic



Class 3, Tue., Sep. 29, 2009
We went over new material from the text on the pigeonhole principle, and also the Fibonacci numbers (sections 2.1 and 2.2).
We also worked on modular arithmetic and the take-away game.
In the pigeonhole principle "magic trick," I asked you to choose seven numbers from the list 1,2,3,...,12. The properties each of your lists had were:
(1) A pair of your numbers had a sum of 13.
(2) A pair of your numbers had a difference of 6.
(3) A pair of your numbers had a difference of 3.
(4) A pair of your numbers had the property that their only common factor was 1.
(5) A pair of your numbers had the property that one divided the other equally.
We saw how the pigeonhole principle explained why properties 1,2, and 3 are true. For Thursday, can you use the pigeonhole principle to explain property 4? Remember, it's all in how you label to (six) pigeonholes!
Property 5 is more difficult to explain; in this case the six pigeonholes have different numbers of numbers assigned to them!

We also went over the "water pouring" problem, and saw how to solve it using the billiard ball technique. Here's a site where you can get free software for implementing the billiard ball approach to the water pouring problem. You have to download the "Mathematica Player" (also free) first.

Due Thursday: Homework problems 1-15 from chapter 1, to be turned in.
Also due Thursday: work all problems in this Modular Arithmetic Intro handout, to turn in.
For Thursday, also work on problems from chapters 2.1 and 2.2 (see list at bottom of this page).
Please print out this handout, and bring them to class on Thursday:
Patterns and Modular Arithmetic

Class 2, Thu., Sep. 24 2009
We went over several of the problems at the end of chapter 1. (See the list of homework from the text for the whole quarter at the bottom of this page.) Complete for homework by Tuesday, but will take up next Thursday (you'll have other assignments to complete by Thursday also, so we need to be done with them by Tuesday.
Also due Tuesday is your Math Autobiography. See page 2 of the green sheet for a complete description.
We also began to discuss modular arithmetic.


Class 1, Tue., Sep. 22, 2009
Had a substitute, Hassan Bourgoub, who played the pattern game and did the frogs on a log problem.
Assignment: Read chapter 1 and work problems 1-15 at the end of chapter 1.

(1) Get your textbook! (See green sheet.)
(2) Read Ch. 1 and begin working on problems at the end, though I won't collect them yet. You should do them
by the end of week 2: #1-15, pg 28-32.
(3) We worked on the pattern game and associated problems.
(4) We also worked on the "Frogs on a log" problem, and found that with
1 frog per side it took a minimum of 3 moves to exchange places
2 frogs per side it took a minimum of 8 moves to exchange places
3 frogs per side it took a minimum of 15 moves to exchange places
You might have guessed that 4 frogs per side would require 24 moves, 5 frogs per side would require 35 moves.
Figure out how to do these exchanges also, in the minimum number of moves. (See below for more explanation.)

Three round frogs (O's) and three crossed frogs (X's)  are sitting on a log with seven spaces, and want to take each other's places. A frog can move one step to a vacant square, or jump over one neighbor to a vacant square. In class we learned that it can be done in 15 moves.

O
O
O
 
X
X
X

Two frogs on a three space log can take each other's places in three moves:

O
  
X

Four frogs on a five space log can change places in 8 moves, as we also discovered in class.

O
O
 
X
X


Here's a list of all the problems from the text book for the quarter. There might be some revisions, and there will be other additions.
Ch. 1 #1-15, pg 28-32.
Ch. 2.1 I: 4,6,9,10-12,14-18,21
Ch. 2.2: 1-7,16,18,21,24,26
Ch. 2.3: 1-3,6,7,13,14,19,20,22,37,39
Ch. 2.4 #3,4,5,7,9,19,28,29,30,32
Ch. 2.5: 3,6,7,8,11,15 
Ch. 4.1 #2,11,12,13,15,18,19
Ch. 4.2 #5,7,9,11,21
Ch. 4.3 # 1-8
Ch. 4.4 # 1-5
Ch. 4.5: 11,12,15,16,21
Ch. 5.1: 4-6, 12,14,16,22,25,26,36
Ch. 5.2: Do any three of 8,9,10,13,14. Also do 18,19,22, any one of 26-28, 37
Ch. 5.3: 2,4,5,7-10
Ch. 5.4: 1-5,13,16,19,20
Ch. 6.1 1,2,3,5,7,8
Ch. 6.2 3,12-23
Ch. 6.3 #1,2,4,5,9,13,21,23
Ch. 6.4 #2,3,6,8,12-15
Ch. 6.5 1-10, 26-28,38-40

Ch. 6.6 #1-6,10-12,15