Courant Institute, NYU
ORDINARY DIFFERENTIAL EQUATIONS (MA 4204 / MATH 252)
Fall 2025
Instructor
Mike O'Neil (oneil@cims.nyu.edu)

Office hours
Tue 11:00am-12:00pm, WWH 1119
Wed 11:00am-12:00pm, 2 MTC 854
(or by appointment)

Description
A first course in ordinary differential equations. This course covers methods for solving first-order linear and nonlinear equations, existence and uniqueness of solutions, and analytical methods for finding solutions. We will also study second-order linear equations, general theory and Wronskians, constant coefficient theory and mechanical vibrations, variation of parameters, and series solutions. More advanced topics toward the end of the semester will include systems of linear equations, eigenvector methods, qualitative analysis of nonlinear systems of equations, boundary-value problems, and an introduction to Fourier Series and Sturm-Liouville theory. Time permitting, we will also discuss the Laplace Transform and how it can be used to solve ODEs, as well as Green’s function methods for solving differential equations. View the syllabus for more detailed information.

Lecture
Monday & Wednesday 9:30am - 10:50am, Jacobs Hall 202

Recitation
Ashley Sobolewski (as21142@nyu.edu)
Friday 9:30am - 10:50am, 2 MTC 817
Office hours: TBA
Materials
The following textbook will be used for the course:
- Martin Braun, Differential Equations and Their Applications, 4th ed., Springer, 1993

The following books might be useful as additional references:
- Boyce, DiPrima, and Meade, Elementary Differential Equations and Boundary Value Problems, 11th ed., Wiley, 2017
- Coddington, An Introduction to Ordinary Differential Equations, Dover, 1989

Grading
The overall course grade will be determined from a final numerical weighted average. The following breakdown will be used to compute an overall numerical grade:
- 10% Homework (weekly, lowest grade dropped)
- 25% Preliminary Exam 1
- 25% Preliminary Exam 2
- 40% Final exam (cumulative)

Announcements
Schedule
Below is an updated list of discussion topics along with any documents that were distributed, homework assigned, etc.
Date Topics Materials
Sep 3 Overview, 1st order equations Braun 1.1-1.2
Sep 8 Integrating factors, Carbon dating Braun 1.1-1.3
Sep 10
Oct 6 Prelim Exam 1
Nov 10 Prelim Exam 2
Nov 26 NO CLASS -- FRIDAY SCHEDULE
Dec XX Final exam