## Course description

This is an applied course in ordinary differential equations, tailored primarily for students in the biological, physical and social sciences, and engineering. Techniques for solving and studying ordinary differential equations are studied. Topics include the quantitative and qualitative study of first order differential equations, second and higher order linear differential equations, systems of first order linear differential equations, autonomous systems, and local linearization of nonlinear first order systems. Applications in population dynamics, mechanical systems and other physical science and engineering disciplines will be discussed, as well as numerical solutions, Laplace transforms and their use in solving differential equations, and mathematical modeling in the sciences or economics.

Textbook: Elementary Differential Equations with Boundary Value Problems, 11th edition, William E. Boyce and Richard C. DiPrima, ISBN:9781119443766

## Instructor

Liming Sun                             Krieger 222      lsun at math.jhu.edu

## Recitation

Section Time Location Name of TA Email
1 T 01:30-02:20pm Croft Hall G02 Costcurta jcostac1@jhu.edu
2 T 03:00-03:50pm Shaffer 300 Dees bdees1@jhu.edu
3 Th 03:00-03:50pm Hodson 301 Chen lchen155@jhu.edu
4 Th 04:30-05:20pm Croft Hall G02 Lane jlane36@jhu.edu
7 T 04:30-05:20pm Croft Hall G02 Costacurta jcostac1@jhu.edu
8 Th 01:30-02:20pm Croft Hall G02 Chen lchen155@jhu.edu

## Lecture

Time: MWF 12:00-12:50am for Section 1, 2, 3 and 4
$$\hspace{1cm}$$MWF 1:30-2:20pm for section 7 and 8

Location: Maryland 110, Homewood Campus

Office Hour: T 10:00am-11:30am and Th 4:00-5:00pm or by appointment

## Resources

Final: 40%
Midterms: 20% each (40% overall)
Quizzes/Homework: 20% overall

## Quiz/Homework

Homework’s due date will be announced explicitly. All homework must be handed in hard copy at the beginning of lecture. Quiz will take place in the last 10 minutes of recitation and will be announced at least one week in advance. No make-up quizzes will be given under any circumstances, but the lowest quiz scores will be dropped.

• You are permitted to work together. However, you must write up your own solutions in your own words. Failure to do so will be treated as plagiarism.
• Solving problems is the best way to learn math (or any subject). For that reason I highly encourage you to think about the assigned problems before working with others/seeking assistance.

## Examination

There will be two in-class Midterm exams. First one is placed on March 2nd, second one is on April 6th.
The final examination will happen at May 11th. All exams are closed book.

## Policy

No late homework
No cell phone or computer in the class
You are expected to attend every class. The course will pick up its pace gradually. As such, it will be very easy to fall behind, even from missing a single class. Please do not be late for the lecture and recitation.

The strength of the university depends on academic and personal integrity. In this course, you must be honest and truthful. Ethical violations include cheating on exams, plagiarism, reuse of assignments, improper use of the Internet and electronic devices, unauthorized collaboration, alteration of graded assignments, forgery and falsification, lying, facilitating academic dishonesty, and unfair competition.

Report any violations you witness to the instructor. You may consult the associate dean of students and/or the chairman of the Ethics Board beforehand. Read the “Statement on Ethics” at the Ethics Board website for more information.

## Disability accommodations policy

Students with documented disabilities or other special needs who require accommodation must register with Student Disability Services. After that, remind the instructor of the specific needs at two weeks prior to each exam; the instructor must be provided with the official letter stating all the needs from Student Disability Services.

## Schedule (will be updated as the course progresses)

Weeks Section covered Homework/Quiz
1/27 M
1/29 W
1/31 F
1.1 Basic models:direction fields
1.2 Solutions to Some ODEs
1.3 Classification of ODEs
2.1 Linear Equations
HW1
2/3 M
2/5 W
2/7 F
2.2 Separable Equations
2.3 Modeling with First-order Differential Equations
2.4 Linear vs. Nonlinear Equations
HW2
2/10 M
2/12 W
2/14 F
2.5 Autonomous Diff Eqns
2.6 Exact Diff Eqns
HW3
Quiz1
2/17 M
2/19 W
2/21 F
3.1 Homogeneous Equations
3.2 The Wronskian
3.3 Char. Eqn. Roots: Complex
HW4
2/24 M
2/26 W
2/28 F
3.4 Repeated roots, Reduction of order
3.5 Nonhomogeneous equations
HW 5
Quiz 2
3/2 M
3/4 W
3/6 F
First midterm
3.5 Nonhomogeneous equations
3.6 Variation of Parameters
HW6
3/9 M
3/11 W
3/13 F
4.1 nth Order Linear ODEs
4.2 Constant Coefficients
4.3 Undetermined Coefficients
HW7
Spring break
3/23 M
3/25 W
3/27 F
Quiz 3

Slides