About me.

Hi, I’m Professor Dresden. I’ve been teaching at W&L for around 30 years, and I’ve taught everything from calculus to cryptography to continued fractions. I often do summer research with students, I occasionally teach some independent study classes, and when I’m not in the office I can sometimes be found at the swimming pool with my wife and two children. Before W&L, I spent many years in school, at Stanford, Wisconsin, and Texas. My email is dresdeng “at” wlu “dot” edu.

Office hours.

It varies by semester; this winter (2025-26) it’ll probably be MWF from 12:30 to 1:45 (more or less) in my office at Chavis 114.

Favorite classes.

It’s hard to choose! I had a tremendous amount of fun a few years back with my Math 332 class (Ordinary Differential Equations). We took some rather simple differential equations and created lovely stream plots that depict the behavior of the solution over time, given a certain initial condition. Here are two pictures from computer labs we did in class. The first one is a regular stream plot …

… and this second one is the same plot, but run through a filter to create a lovely effect.

Oh, and despite the occasional use of computers, my teaching is actually pretty old-school. I mainly use the chalkboard, which leads to some wonderful (hand-drawn) mathematical displays. My students saw a lot of this in my Real Analysis class (Math 311-312), where I gave detailed presentations like this one on the implicit function theorem:

and this one on uniform convergence:

… but don’t worry, that’s just what the chalkboard looks like at the end of class.

Math information (graduate schools, careers in math, and so on).

• Be sure to check out the many professional math societies here in the US!
  • There’s the MAA (Mathematical Association of America) web pages, with a great careers page (perfect for students).
  • Likewise, the AMS (American Mathematical Society) also has a nice student page. Note that the AMS and the MAA have a great deal of overlap in terms of services and membership. but the AMS is a bit more research-oriented and the MAA is a bit more teaching-oriented.
  • The NAM (National Association of Mathematicians) is dedicated to supporting underrepresented minorities in math. My colleague Cory Colbert is the Treasurer of the NAM!
  • The AWM (Association for Women in Mathematics) is focused on supporting women and girls in math.
  • SIAM (Society for Industrial and Applied Mathematics) is more focused on applied math. And yes, they have a student page as well!
• The incredibly useful Rosetta Code site has code snippets in Mathematica and Maple (and more).
• The online magazine Quanta has many thoughtful general-interest articles on mathematics. So also does Nautilus, including this neat story on near-miss mathematics.
• The most inspiring math talk (without a single equation!) I’ve ever seen is Francis Su’s The Lesson of Grace in Teaching (link goes to the speech text, which links to the video). It’s so moving that audience members were literally crying during his speech (as was Francis himself).

Local information.

• Approximate coordinates for downtown Lexington: 37.783056 (North), -79.445278 (West).
• Rockbridge County is truly a rural county; the total (city + county) population is around 36,000, and Lexington itself only makes up around 7,000. Rockbridge is not part of any of Virginia’s Metropolitan Statistical Areas.
• Some links for outdoor activities: Hikingupward.com. Douthat State Park. Sherando Lake.
• Some links for local activities: Lexington events, Shenandoah events,

W&L links that you might find useful!

• We’re in the Department of Mathematics, The College (of Arts & Sciences), Washington & Lee University.
• Keep up with campus news at The Columns.
• W&L journalism students produce the informative and very professional Rockbridge Report, with good local news.
•  W&L Inclement Weather bulletin.
• Mailing Address: Chavis Hall room 114 (Math Dept), Washington & Lee University, 204 West Washington Street, Lexington VA 24450-2116. Chavis Hall, home to the math department, is named after John Chavis, the first African-American to graduate from college (at what was then called Washington College, in 1799).

Favorite charities.

• Charcot-Marie-Tooth Association, for people with this genetic disease of the peripheral nervous system.
• American Red Cross. A family member needed a blood transfusion during a recent surgery; thank goodness for the ARC and the many anonymous donors.
• National Kidney Foundation, for people with kidney disease.

And here’s a bit more. The cause that is nearest and dearest to my heart is organ donation. I have some details about my 2018 kidney donation on my advice page (scroll to the bottom), and also you can go directly to kidney.org, to bethematch.org, and to organdonor.gov. Or, you can just ask me about it. You can save someone’s life.