Do this first:

The linear algebra package "linalg" is needed in order to use vectors in Maple.

> with(linalg):

Warning, new definition for norm

Warning, new definition for trace

(Don't worry about these warnings. The one about "norm" means that we can now use the "norm" function to find the norm of vectors. Prior to loading the linalg package, the "norm" function would find the norm of polynomials -- not the same thing!)

The "plots" package is needed in order to use Maple's fieldplot, fieldplot3d, gradplot, and gradplot3d commands.

> with(plots):

>