eleteroboltz

L and H are constants, reals and greater than 0. n and m are integers greater than 0.

Hi guys, I'm looking for a function [latex] b(x,y) [/latex] that satisfies: [latex] \int_0^L \int_0^H b(x,y) \, dx \, dy = 0[/latex] and [latex] \int_0^L \int_0^H b(x,y) \cos \left(\frac{n \, \pi \, x}{L} \right) \cos \left(\frac{m \, \pi \, y}{H} \right) \, dx \, dy \ne 0[/latex] for [latex] n=1,2,3,... [/latex] and [latex] m=1,2,3,... [/latex] Thank you in advance...