Steady wave eq and fourier transform

Click For Summary
SUMMARY

The discussion focuses on solving the steady wave equation $$u_{xx} + u_{yy} = 0$$ for the region where $$x < 0$$ and $$-\infty < y < \infty$$ using the Fourier Transform. The Fourier Transform is defined as $$F(f(x)) = \frac{1}{2\pi} \int_{-\infty}^{\infty} f(x) \exp(i \omega x) dx$$. The user successfully applies the Fourier Transform in the variable $$y$$, leading to the expression $$F(u) = F(g(y)) \exp(\omega x)$$. The user resolves their confusion regarding the inverse of $$\exp(\omega x)$$ and concludes that they found the correct approach to the problem.

PREREQUISITES
  • Understanding of partial differential equations, specifically the steady wave equation.
  • Familiarity with Fourier Transform techniques and their definitions.
  • Knowledge of convolution operations in the context of Fourier Transforms.
  • Basic skills in mathematical analysis and function manipulation.
NEXT STEPS
  • Study the properties and applications of the Fourier Transform in solving PDEs.
  • Learn about convolution and its role in Fourier analysis.
  • Explore the inverse Fourier Transform and its computation methods.
  • Investigate the Fourier cosine and sine transforms for boundary value problems.
USEFUL FOR

Mathematicians, physics students, and engineers working with wave equations and Fourier analysis, particularly those tackling partial differential equations.

member 428835

Homework Statement


$$u_{xx} + u_{yy} = 0 : x < 0, -\infty < y < \infty$$

Homework Equations


We can use Fourier Transform, which is defined over some function ##f(x)## as ##F(f(x)) = 1/ 2\pi \int_{-\infty}^{\infty} f(x) \exp (i \omega x) dx##.

The Attempt at a Solution


Using the Fourier transform in the variable ##y## I find that $$F(u) = F(g(y)) \exp (\omega x)$$ From here I would use convolution but I don't know the inverse of ## \exp (\omega x) ##. Any help here (or if I should have used a Fourier cosine/sine transform instead?
 
It's ok, I think I solved this. Just had to find the correct chart.
 

Similar threads

Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 12 ·
Replies
12
Views
2K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
5
Views
2K
Replies
8
Views
2K
Replies
2
Views
2K