Math 23 : Differential Equations

Spring 2013

Wave Scattering in layered media by Min Hyung Cho

Section 001 Section 002
Instructor Min Hyung Cho David Webb
Lectures MWF 11:15-12:20 MWF 12:30-1:35
x-Hour Tue 12:00-12:50 Tue 1:00-1:50
Location 006 Kemeny Hall 105 Kemeny Hall
Office Hour W:3:30-5:00, Th:2:00-3:00
and by appointment, Kemeny 315
TBA and by appointment, Kemeny 309
Contact email : min.h.cho at dartmouth dot edu 
Phone : 603-646-9847
email: David.L.Webb at dartmouth dot edu
Phone: 603-646-1271
Syllabus Syllabus (pdf) Syllabus (pdf)
Schedule and Homework Tentative Schedule, Homework, and Handouts

Course Overview

Differential equations, which relate the rates of change of a function with respect to one or more of its variables to the values of the function itself, are the language of modern science, and have been since the work of Newton that ushered in the modern scientific era. Math 23 is an introduction to ordinary differential equations, along with a very brief glimpse of one or two important partial differential equations.


1. Mark Krusemeyer, Differential Equations, available at Wheelock Books. - Download Errata

2. Jiri Lebl, Notes on Diffy Qs, available free online at (

3. Various handouts (Class note from Prof. Sutton in 2012 Winter) posted on Blackboard under Course Materials and this website (Go to and use your Dartmouth email authentication).


Schedule : Tue, Th, and Sun 7:00-9:00PM, Kemeny 008, TA: Ewa Infeld.


Weekly homework assignments will be posted on this website and Blackboard. Homework will be collected on Fridays during the class. One homework grade will be dropped, but late homework will not be accepted. Each Assignment will be divided into two parts and it is required that you hand in a separate write-up for each part.


There will be two midterm exams and a final exam. Homework will be worth 20% of the final grade. Each of the midterm exams will be worth 20%, while the final will be worth 35%. The remaining 5% of the grade will be based upon class participation, quizzes, etc.

Honor Principle

You are encouraged to work together on homework. However, the final writeup should be your own. On exams, all work should be entirely your own; no consultation of other persons, printed works, or online sources is allowed without the instructor's explicit permission.

Students with disabilities

Any student with a diagnosed learning disability requiring accommodations should see me as early in the term as possible. All discussions will remain confidential, although the Student Accessibility Services office may be consulted.

Free advice

Mathematics is a very difficult subject to absorb in real time, and even professional mathematicians often get lost in lectures. Thus, in order to optimize the utility of the lectures, it is very important to have read and thought about the reading assignment before the lecture, jotting down notes and questions as you go. This will prepare you for what is to come in the lecture, will make the lecture much easier to follow, and will perhaps raise questions in your mind that you can ask during the lecture if they are not already resolved. After the lecture, a careful rereading of the assignment will solidify the concepts.