Using the method of images and Green's functions, find the solution of Poisson's equation in 2D for $\nabla^2 u = h(x, y);\,$ with $u(0, y) = f(y), \,\, u(x, 0) = g (x)$
I just don't see how to use the method of images. I've been reading "Green’s Functions and Linear Differential Equations" by Prem K. Kythe, but the explanation is not detailed enough. If anybody could tell me how to proceed, I would be very thankful.