## MAS222 Differential Equations

 Both semesters, 2020/21 20 Credits Lecturer: Dr Jonathan Potts Timetable Reading List Aims Outcomes Teaching Methods Assessment Full Syllabus

The module aims at developing a core set of advanced mathematical techniques essential to the study of applied mathematics. Topics include the qualitative analysis of ordinary differential equations, solutions of second order linear ordinary differential equations with variable coefficients, first order and second order partial differential equations, the method of characteristics and the method of separation of variables.

Prerequisites: MAS110 (Mathematics Core I); MAS111 (Mathematics Core II)
Corequisites: MAS211 (Advanced Calculus and Linear Algebra)

The following modules have this module as a prerequisite:

 MAS212 Scientific Computing and Simulation MAS316 Mathematical modelling of natural systems MAS320 Fluid Mechanics I MAS377 Mathematical Biology MAS414 Mathematical Modelling of Natural Systems MAS422 Magnetohydrodynamics

## Outline syllabus

• First order ordinary differential equations.
• Planar first order autonomous systems, linearisation of nonlinear planar systems.
• Stability of equilibrium points.
• Second order linear ordinary differential equations, power series solutions, ordinary and singular points.
• Sturm-Liouville problems.
• Second order partial differential equations: wave equation, heat equation, Laplace's equation, separation of variables.
• First order partial differential equations, method of characteristics.
• Method of characteristics for second order hyperbolic partial differential equations.

## Office hours

If this timeslot is not possible, please email the lecturer to arrange a mutually convenient time.

## Aims

• To learn the qualitative analysis of ordinary differential equations
• To learn how to solve second order oridnary differential equations with variable coefficients
• To learn how to solve first order partial differential equations using the method of characteristics
• To learn how to solve second order partial differential equations using the method of separation of variables
• To learn the properties of the solutions of the classical partial differential equations

## Learning outcomes

• To be able to characterise systems of ordinary differential equation qualitatively.
• To be able to solve second order ordinary differential equations with variable coefficients using various techniques
• To be able to solve first order partial differential equations using the method of characteristics
• To be able to solve second order partial differential equations using the method of separation of variables and the method of characterisics

## Teaching methods

Lectures, tutorials, problem solving

40 lectures, 10 tutorials

## Assessment

One 1 hour exam on computer at the end of Semester 1 (10%)
One 2.5 hour written examination at the end of Semester 2 (90%)

## Full syllabus

Semester 1

• Revision of ordinary differential equations (ODEs)
• Qualitative analysis of first order ODEs: direction fields, autonomous equations, equilibrium points, phase lines.
• Planar first order autonomous systems: equilibrium points, trajectories, nullclines, classification of equilibrium points for linear systems, phase portraits in the neighborhood the equilibrium points
• Linearisation of nonlinear planar system
• Stability of equlibrium points: linear systems, effects of nonlinear terms
• Phase portraits of planar first order autonomous systems
• Second order linear ordinary differential equations with variable coefficients: boundary value problems, normal form, reduction of order
• Power series solution and Frobenius series solution: ordinary points and singular points, Hermites' equation, Airy equation, Bessel's equation, Legendre equation, and Laguerre's equation (as examples or tutorial questions)
Semester 2
• Introduction and basic definitions
• Separation of variables for homogeneous problems: the heat equation, wave equation, Laplace's equation
• Separation of variables for inhomogeneous problems: the heat equation, wave equation Laplace's equation
• Method of characteristics for first order PDEs
• Method of characteristics for second order hyperbolic PDEs
• D'Alembert's solution of the one-dimensional wave equation.

Type Author(s) Title Library Blackwells Amazon
B Boyce and Diprima Elementary Differential Equations and Boundary Value Problems Blackwells Amazon
B D. W. Trim Applied Partial Differential Equations Blackwells Amazon
B King, Billngham, and Otto Differential Equations: Linear, Nonlinear, Ordinary, Partial Blackwells Amazon
B Simmons Differential Equations with Applications and Historical Notes Blackwells Amazon
C A. Jeffrey Applied Partial Differential Equations: An Introduction Blackwells Amazon
C Logan Applied Partial Differential Equations Blackwells Amazon
C Steven Stogatz Nonlinear dynamics and chaos Blackwells Amazon

(A = essential, B = recommended, C = background.)

Most books on reading lists should also be available from the Blackwells shop at Jessop West.

## Timetable (semester 1)

 Tue 10:00 - 10:50 lecture Blackboard Online Tue 14:00 - 14:50 tutorial (weeks 1,3,5,8,10,12) Blackboard Online Tue 14:00 - 14:50 tutorial (group A) (weeks 1,3,5,8,10,12) Blackboard Online Tue 15:00 - 15:50 tutorial (group B) (weeks 1,3,5,8,10,12) Blackboard Online Tue 16:00 - 16:50 tutorial (group C) (weeks 1,3,5,8,10,12) Blackboard Online Fri 10:00 - 10:50 lecture Blackboard Online