Transformation of a Cauchy-Euler equation

In summary, a Cauchy-Euler equation is a second-order linear differential equation with variable coefficients, and it can be solved by finding the roots of the characteristic equation and using them to construct a general solution. The term "transformation" refers to the process of changing the independent variable in the equation, and non-integer or complex solutions are possible depending on the coefficients. Cauchy-Euler equations have various real-world applications in physics, engineering, and differential operators.
  • #1
jawhnay
37
0

Homework Statement


x2y'' - xy' = ln x




Homework Equations


The problem I'm having is what do I do with x = et or t = ln x.


The Attempt at a Solution


I know you have to start with x = et or t = ln x however I'm not sure what to do next...
 
Physics news on Phys.org
  • #2
You need to express ## y' = \frac {dy} {dx}, \ y'' = \frac {d^2y} {dx^2} ## in terms of ## \frac {dy} {dt} ## and ## \frac {d^2y} {dt^2} ##.
 

1. What is a Cauchy-Euler equation?

A Cauchy-Euler equation is a second-order linear differential equation with variable coefficients that can be written in the form ax2y'' + bxy' + cy = 0, where a, b, and c are constants.

2. How is a Cauchy-Euler equation solved?

The standard method for solving a Cauchy-Euler equation involves finding the roots of the characteristic equation, which is obtained by substituting y = xr into the equation and solving for r. The general solution is then found by using the roots to construct a linear combination of the form y = c1xr1 + c2xr2, where c1 and c2 are arbitrary constants.

3. What is the significance of the term "transformation" in the context of a Cauchy-Euler equation?

The term "transformation" refers to the process of changing the independent variable in a Cauchy-Euler equation to a new variable, such as u = ln(x) or u = ex. This transformation can make it easier to solve the equation and may reveal hidden symmetries or patterns.

4. Can a Cauchy-Euler equation have non-integer or complex solutions?

Yes, a Cauchy-Euler equation can have non-integer or complex solutions, depending on the coefficients and the roots of the characteristic equation. In these cases, the general solution can be expressed in terms of hypergeometric functions or other special functions.

5. How is a Cauchy-Euler equation applied in real-world problems?

Cauchy-Euler equations have many applications in physics, engineering, and other fields. They can be used to model various physical phenomena, such as the motion of a pendulum or the vibrations of a guitar string. They also arise in problems involving differential operators, such as the Laplace or Fourier transforms.

Similar threads

  • Calculus and Beyond Homework Help
Replies
2
Views
1K
  • Calculus and Beyond Homework Help
Replies
4
Views
738
  • Calculus and Beyond Homework Help
Replies
2
Views
572
  • Calculus and Beyond Homework Help
Replies
5
Views
345
  • Calculus and Beyond Homework Help
Replies
18
Views
2K
  • Calculus and Beyond Homework Help
Replies
5
Views
265
  • Calculus and Beyond Homework Help
Replies
5
Views
957
  • Calculus and Beyond Homework Help
Replies
8
Views
1K
  • Calculus and Beyond Homework Help
Replies
2
Views
1K
  • Calculus and Beyond Homework Help
Replies
1
Views
535
Back
Top