Purchase Solution

Differential Equation : Space Factor, Time Factor, Eigenvalues and Sturm-Liouville

Not what you're looking for?

Ask Custom Question

7. Consider the differential equation
ut =1/2 uxx + ux for 0 <x < pi, t > 0
with boundary conditions
u(0,t) = u(pi,t) = 0.
(a) Separate variables and write the ordinary differential equations that the space factor X(x) and the time factor T(t) must satisfy.
(b) Show that 0 is not an eigenvalue of the Sturm-Liouville problem for X.
(c) Show that for any integer n>1,
Xn(x) = e^-x sinnx
is an eigenfunction of the Sturm-Liouville problem for X and determine the corresponding eigenvalue.
(d) Assuming that these are all the eigenvalues, write down in series form the general solution of the boundary value problem above assuming a general initial condition u(x, 0) = f(x).

Please see the attached file for the fully formatted problems.

Attachments
Purchase this Solution

Solution Summary

A differential equation is investigated with regard to space factor, time factor, eigenvalues and sturm-liouville problem. The solution is detailed and well presented.

Solution Preview

Please see the attached file for the full solution.

Solution:

We have to solve the PDE:
( 1)
with initial and boundary conditions:
( 2)
This kind of problem is known as "mixed problem", because it contains initial conditions as well as boundary ones.
The easiest way to solve the above equation is to apply the Fourier method, that means separation of variables:
( 3)
By doing partial derivatives and introducing in (1), we will have:
( 4)
We've chosen a negative constant in order to provide a periodic solution for bilocal problem (the boundary condition). For a positive constant, we will see ...

Purchase this Solution


Free BrainMass Quizzes
Graphs and Functions

This quiz helps you easily identify a function and test your understanding of ranges, domains , function inverses and transformations.

Know Your Linear Equations

Each question is a choice-summary multiple choice question that will present you with a linear equation and then make 4 statements about that equation. You must determine which of the 4 statements are true (if any) in regards to the equation.

Probability Quiz

Some questions on probability

Exponential Expressions

In this quiz, you will have a chance to practice basic terminology of exponential expressions and how to evaluate them.

Multiplying Complex Numbers

This is a short quiz to check your understanding of multiplication of complex numbers in rectangular form.