Generic Solution of a Coupled System of 2nd Order PDEs

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SUMMARY

The discussion focuses on solving a set of second-order partial differential equations (PDEs) for the functions u(x,y) and v(x,y), with constants A, B, and C, where A and B are greater than zero. The proposed method involves seeking separable solutions of the form u = Ue^{kx + ly} and v = Ve^{kx + ly}, leading to an eigenvalue problem characterized by the equation k^4(1 + B^2C) + k^2 l^2 (2 + C(A^2 + B^2)) + l^4(1 + A^2C) = 0. This equation can be factored into (k^2 + l^2)(k^2(1 + CB^2) + l^2(1 + CA^2)) = 0, indicating the potential use of Laplace and Fourier transforms for further analysis.

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We are looking for the generic solution of this coupled system of 2nd order PDEs.
Hi! I am looking into a mechanical problem which reduces to the set of PDE's below. I would be very happy if you could help me with it.

I have the following set of second order PDE's that I want to solve. I want to solve for the generic solutions of the functions u(x,y) and v(x,y). A, B and C are constants, and (if it helps) A, B > 0.
pde.PNG
 
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It's linear, so you can try looking for separable solutions. If you set u = Ue^{kx + ly} and v = Ve^{kx + ly} then you get the following eigenvalue problem for k and l:
<br /> k^4(1 + B^2C) + k^2 l^2 (2 + C(A^2 + B^2)) + l^4(1 + A^2C) = 0.

EDIT: This factorises as <br /> (k^2 + l^2)(k^2(1 + CB^2) + l^2(1 + CA^2)) = 0.
 
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Laplace transform; Fourier transform...
 
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