# Thread: Verify 2D Laplace Solution

3. ## Re: Verify 2D Laplace Solution

In part A I am not sure how to verify that the analytic solution is of the form described? Additionally I have done Laplace's transforms before but i have no idea how to do part B as well. Thanks for all your help!

4. ## Re: Verify 2D Laplace Solution

Originally Posted by helpthanks
In part A I am not sure how to verify that the analytic solution is of the form described?
To verify the solution, just apply the Laplace operator to it and see that it gives 0 indeed. Note that your solution is separable $\displaystyle u(x,y) = X(x)Y(y)$, which should ease the procedure.
Originally Posted by helpthanks
Additionally I have done Laplace's transforms before but i have no idea how to do part B as well.
No need for Laplace transforms. This is the Laplace equation.

5. ## Re: Verify 2D Laplace Solution

Would you mind doing or starting this problem for me, i have quite a few like this i have to do but am having trouble going through the whole process of one problem. Thanks again!

6. ## Re: Verify 2D Laplace Solution

Attached is my work so far.

7. ## Re: Verify 2D Laplace Solution

You fixed $\displaystyle a$ and $\displaystyle b$ such that the boundary conditions are satisfied. Good. But you need to check that the solution satisfies the Laplace equation, i.e. $\displaystyle \nabla^2 u = {\partial^2 u \over \partial x^2} + {\partial^2 u \over \partial y^2} = 0$.

8. ## Re: Verify 2D Laplace Solution

The first page is where i verified that it is equal to zero and the second page I solved for A & B. What should i do differently on the first page that i did not do to show it is equal to zero?

9. ## Re: Verify 2D Laplace Solution

On the first page you checked that the Dirichlet boundary conditions $\displaystyle u(x,0) = 0$ and $\displaystyle u(x,L_y ) = 0$. This shows that 2 boundary conditions are satisfied. You need to compute the Laplacian of the function to show that the equation is true everywhere in the domain.