Steady wave eq and fourier transform

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.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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