Partial Differential Equations
A differential equation is one in which differential coffecients of various orders occur together with functions of both independent and dependent variables but no arbitrary constants. The order of a differential equation is the highest order of derivative that is present while the degree of differential equation is that of the highest power of the highest order of derivative that is present.
A basic introduction to Laplace's equation, the heat equation and the wave equation can be found at:
The spatial and temporal variations of concentration, C, are described by Fick's second law of diffusion. The general solution to Fick's second law of diffusion can be found at: