ABSTRACT
The solution of partial differential equations can be split into a number of quite
different approaches depending on the types of equations involved. The general
formula for second-order linear PDEs can be written:
=+
∂
∂
+
∂∂
∂
+
∂
∂
D
y
u
C
yx
u
B
x
u
A (16.1)
where x and y can be spatial coordinates, or one in space and one in time.
Furthermore, u will generally be a function of x and y, and A, B, C and D are
constants. The type of problem and therefore the type of solution can be
determined based on the quantity B
