MATH400-101 :       Applied Partial Differential Equations   (First term 2022-2023)


Lecture   I: Monday 9:00am--10:00am, LASR-102.

Lecture   II: Wednesday 9:00am--10:00am, LASR-102.

Lecture   III: Friday 9:00am--10:00am, LASR-102.

Office Hours: In-Office, Every Monday, Wednesday, 3:30pm-5pm at LSK 303B. Zoom: Every Friday, Sunday: 8:30-10pm


Lecture Notes For MATH400-101


Lecture Notes 1

(revised) Example 10 (in Lecture 1)

Lecture Notes 2

Lecture Notes 3

Summary of 1st Order PDE

Lecture Notes 4

Notes on General Solutions of Wave Equation

Lecture Notes 5

Lecture Notes 6

Method of Reflection on Intervals

Examples of Method of Reflections

Lecture Notes 7

Lecture Notes 8

Lecture Notes 8.5

Lecture Notes 9

Lecture Notes 9.5

Lecture Notes 10

Notes on Second Order ODEs

Lecture Notes 11

Lecture Notes 12

Lecture Notes 13

Lecture Notes 14

Lecture Notes 15

Lecture Notes 16


Downloads For MATH400


Download 1: Syllabus

Download 2: HW1 (Due: Sept. 17, by 1am)

Download 3: HW2 (Due: Sept. 26, by 1am)

Download 4: HW3 (Due: Oct. 2, by 11pm)

Download 5: HW4 (Due: Oct. 16, by 11pm)

Download 6: HW5 (Due: Oct. 25, by 11pm)

Updates For MATH 400-101


First class: Sept 7, 2019

Sept 7: Introduction to PDEs; 1st order linear PDE; introduction to characteristic curves and initial data curve.

Sept 9: Characteristic curves for Case 1 $ a(x,y) u_x+ b (x, y) u_y=0$. Examples. Domain of Existence.

Sept 12: Solving $ au_x+b u_y=c$ by method of characteristic Curves. Reduce it to systems of three ODEs. Examples 6,7, 8.

Sept. 14, 2022: Examples 10, 11. Difficulties of General Method. General solutions for $au_x+b u_y=c$ by method of change of variable.

Sept.16, 2022: Method of finding general solutions to $ au_x+b u_y=c$. Finished Lecture Note One. Start with lecture Note Two. General solution of $ u_t+ u u_x=0$. Break-up time.

Sept. 21, 2022: Breaking time. Three examples. Expansion Fan. Examples.

Sept. 23, 2022: Derivation of Rankine-Hugoniot condition. Shock curve. First example of Shock curve.

Sept. 26, 2022: Examples of expansion fan and shock curves. Traffic models. Red light and green light.

Sept. 28, 2022: Fully nonlinear 1st order PDE. Charpit's equations. Completion of Lecture Note 3.

Oct. 3, 2022: Review of 1st Order PDEs. Introduction to 2nd Order PDE. Derivation of Heat/Wave equation. Divergence Theorem.

Oct. 5, 2022: Initial and Boundary Conditions. PDE Problem. Well-posedness, Ill-posedness. Examples of Ill-posedness.

Oct. 7, 2022: Midterm One

Oct. 12, 2022: Types of Second order PDE. Change of variables. General solutions of wave equations.

Oct. 14, 2022: General solutions of wave equations. Wave equations on quarter plane. d'Alembert's formula.

Oct. 17, 2022: Geometric Meaning of wave equation formula. Finite speed of propagation. Domain of dependence and influence. Energy conservation.

Oct. 19, 2022: Wave equation with source. well-posedness. Method of reflection.

Oct. 21, 2022: Method of reflections: quarter plane and intervals. Two examples. Heat equation.

Oct. 24, 2022: Reduce heat equation to ODE. Heat equation with piecewise constants initial data. Solution formula for heat equation. Examples.

Oct. 26, 2022: Heat equation with source. Duhammel's formula. Examples. Energy of heat equation. Comparison of heat and wave equation. Lecture Note 8.

Oct. 28, 2022: Heat equation with boundaries. method of reflections (extension). odd/Even extensions. Introduction to method of separation of variables,

Oct. 31, 2022: Method of separation of variables. Fourier-Sine-Series, Fourier Cosine-Series, Half-period Fourier Sine-Series, Half-period Fourier Cosine-Series. Examples.

Nov. 2, 2022: Eigenvalue Problems for Robin BCs. Five regions. Lecture Note 9.5

Nov. 4, 2022: Robin BC EVP. Heat Equation and Wave Equation with Robin BCs.

Nov. 7, 2022: Generalized Sturm-Liouville Eigenvalue Problems. Examples.

Nov. 14, 2022: Midterm II

Nov. 16, 2022: Bessel Function of Order n

Nov. 18, 2022: Inhomogeneous Heat and Wave Equations. Method of separation of variables.

Nov. 21, 2022: Method of Shifting Data. Inhomogeneous Heat with Neumann Boundary Conditions.

Nov. 23, 2022: Uniqueness of Laplace Equation by energy method. Method of Separation of Variables for rectangles. Heat equation on rectangles.

Nov. 25, 2022: Heat/Wave equation on rectangles. Uniqueness of heat/wave equation with BCs. Laplace equations in polar coordinates. 3D Laplace in cylinderical coordinates and polar coordinate.

Nov. 28, 2022: Laplace equation on a disk. Poisson's formula.

Nov. 30, 2022: Max, Min Principle. Mean-value Principle. Heat/wave equation on a disk. Annulus.

Dec. 2, 2022: Heat equation on a disk with inhomogeneous BCs. Annulus. Exterior of disk

Dec. 5, 2022: Exterior of disk. Wedge. Laplace/Heat equation in 3D cylinderical coordinate and spherical coordinate.


Announcements For MATH 400-101



   Back to My Home Page