Recent content by johnnymopo

  1. J

    2nd order diff eq, 3 dim. and wierd boundry condition

    Is that not a Helmholtz equation, and is a Helmholtz not a time-independent wave?
  2. J

    2nd order diff eq, 3 dim. and wierd boundry condition

    I need help. For the following problem, can someone suggest how I should start on this question. I only have one quarter of diff eq classes plus a few classes in Fourier analysis. I'm out of my league. Consider a box with length, width and height given by L. The box encompasses the region...