Mathematica has a homepage.
To aid you in learning to use Mathematica, Mark Herrmann created a notebook to numerically integrate the equations of motion for a charged particle in a uniform electric and magenetic field and plot the results.
Below is a sample of the output from the Mathematica notebook. It depicts a particle moving in an electric and magnetic field. If the particle started at (0,0,0) at t=0. Can you tell the directions of the fields and the sign of the charge?
If you have any problems, please let me know:
Phil Snyder
T193
Princeton Plasma Physics Lab.
Princeton, NJ 08543-0451
(609) 243 2728