ANNOUNCEMENTS
MTH 338 — Spring 2014

6/13/14
Strange but true: The 13th of the month is more likely to be a Friday than any other day of the week!
Give up? Further information is available here.
I have finished grading the essays, and am working on course grades, which should be submitted later today (Friday).
You can pick up your final essay from me next week (or in the fall); I can also send you a scanned copy on request.
6/6/14
I will be in my office on Sunday, 6/8, from 2–4 PM.
The building may be locked, so bring a cellphone and call my office (541-737-5159) if you can't get in.
Or stand under my window (above the north door) and yell.
I will also be in my office from 9 AM–12 PM on Monday, 6/9.
6/4/14
The paper I referred to about the geometry of hyperbolic trig functions can be found here.
See also Chapter 15 of my special relativity book.
6/1/14
Extra office hours this week: MW 10–12 & 1:30–3:30; T 1–2.
Other times may be possible; ask.
Both class and my office hours on Friday (6/6) are canceled.
5/30/14
The material I discussed today, including the figures I showed at the end, can be found in Chapter 14 of my book on special relativity.
5/29/14
Your final paper should be single-spaced, not double-spaced, and should be roughly 5–7 pages long, not counting a title page (if any), figures, references, or lengthy equations.
Your rough draft may be double-spaced, in which case it should be at least 5 pages long, counting everything; any shorter, and you risk having to add too much material next week without the benefit of feedback.
5/26/14
Extra office hours this week: WF 10–12 & 1:30–3:30.
Other times may be possible; ask.
There are two assignments this week...
5/20/14
A Java package with many features similar to Geometer's Sketchpad is Cinderella, which has the nice feature of being able to show you Euclidean, hyperbolic, and elliptic versions of the same construction simultaneously.
Be warned that angle and distance measurements will be Euclidean unless you select a different type of geometry using the buttons at the bottom; changing the view alone is not sufficient.
5/19/14
My office hour this afternoon is canceled.
I will be in my office every day this week right after class, including today.
When sending me electronic assignments, I remind you that PDF is the only safe format to use.
Please make sure your name is in the file. Please make sure your name is part of the filename.
5/14/14
Friday's class (5/16) will meet in the classroom in the back of the MLC.
This is Kidder 108H, not the computer lab, which is Kidder 108J.
5/7/14
The midterm will be in class on Monday, 5/12.
5/6/14
An interesting application of hyperbolic geometry to tree diagrams can be found here.
5/5/14
The second page of today's lab, involving Mathematica, is optional.
How do you copy lengths and angles from one place to another. Lengths are easy: use circles!
Imagine performing constructions with a compass and straightedge. You're allowed to set the compass to the size of a given line segment, then draw a circle of that radius elsewhere. You can mimic this construction in Geometer's Sketchpad by first selecting the point and line segment, then going to the Construct menu and choosing Circle by Center+Radius.
(A similar tool exists for hyperbolic geometry, but not for elliptic geometry. However, you can accomplish the same thing for spherical geometry using the Translation transformation of Spherical Easel to duplicate circles.)
Right angles are also easy: construct perpendicular lines. But general angles are a bit more complicated.
Take a look at my solution in \\poole\ClassFolders\Math-Dray\MTH338\SAS.gsp, and see if you can figure out how I did it. You should be able to move points A, B, and C around while preserving the congruence of the two triangles.
One way to duplicate an angle (in Euclidean geometry) is described here.
Can you adapt this method to hyperbolic or elliptic geometry?
5/4/14
A good alternative to Geometer's Sketchpad is the freely-available GeoGebra.
You can find a worksheet for the Poincaré Disk here.
The hyperbolic tools are in the Tools > Custom Tools menu, and can also be accessed via the second toolbar icon from the right. Note especially the "Compass" tool, which allows duplication of circles.
5/2/14
The figures I (tried to) draw in class today, showing why the exterior angle theorem fails, can be found here.
These figures were drawn using the Java applet Spherical Easel to model spherical geomtry.
4/30/14
Monday's class (5/5) will meet in the computer lab in the back of the MLC (Kidder 108).
4/29/14
A Java applet for the Poincaré Disk can be found here.
4/28/14
Today's lab handout is available here.
An (older) version of today's activity using Mathematica can be found here.
Today's lab writeup is due Friday, rather than Wednesday as announced in class.
4/25/14
A list of potential topics has been posted here.
This would be a good time to reread my advice on how to write mathematical essays.
A newer version of this document is being drafted here.
4/23/14
A sample homework solution can be found here.
Monday's class (4/28) will meet in the computer lab in the back of the MLC (Kidder 108).
4/20/14
With apologies, the second taxicab geometry assignment wasn't posted in a timely fashion.
It was supposed to be due tomorrow in class, but I will accept it through class on Wednesday.
There is also a separate assignment due next Monday.
See the homework page for further details.
4/19/14
Here are the ways you can save your work when using Geometer's Sketchpad:
Most standard LaTeX installations can handle PDF files; some prefer PostScript (PS). For other formats, you will need to use an external file converter.
4/18/14
There was a minor syntax glitch in the second handout in today's lab. The correct syntax for loading taxicab.m is:
<<"\\\\poole.scf.oregonstate.edu\\ClassFolders\\Math-Dray\\MTH338\\taxicab.m"
A revised copy of the handout is available here; the first handout (also slightly revised) is available here.
4/17/14
A reminder that this week's blog assignment asks each group to post their final definition at the bottom of their definition page, after which each member of the group should add a comment agreeing that this is the final version.
The person who posts the definition should either also post such a comment (preferred) or indicate in the definition post that this is the final version.
4/16/14
This Friday's class (4/18) will meet in the computer lab in the back of the MLC (Kidder 108).
4/12/14
You may find these newspaper articles about court decisions involving taxicab geometry to be of interest.
4/11/14
You can find out more about using Dandelin spheres to prove some geometric properties of conic sections here or here.
4/9/14
A sheet of taxicab graph paper is available here.
4/7/14
There is a website devoted to taxicab geometry that you may find interesting.
This website is maintained by a former student in this course!
4/2/14
Challenge for Friday:
Draw a picture of the 13-point projective geometry.
Draw a picture of the 16-point affine geometry.
These geometries are defined in the problems for RG §1.4.
4/1/14
With apologies, my office hour tomorrow (Wednesday) is shifted forward — I will be in my office from 10–11 AM, rather than 10:30–11:30 AM. This change affects this week only.
I will likely be in my office tomorrow afternoon; contact me if you would like to set up an appointment.
3/28/14
Please read this document with some comments on wordprocessing formats.
Nothing else is as good as LaTeX at typesetting mathematics. Especially if you are planning to become a mathematician, you are strongly encouraged to learn LaTeX. I am happy to help with LaTeX coding questions, but not with installation or editor-specific problems.
You may use any wordprocessing software you wish, so long as I can read the equations.
3/27/14
You may find some of the writing resources listed below to be helpful.
3/26/14
A description of some criteria that I will use to evaluate written work can be found here.