1) One should login to "electron" (Unix command: ssh electron) where unlimited number of licenses for mathematica 3 are available.

Only 2 licenses of mathematica 4 are available on "graviton". For the homework mathematica 3 is enough.

2) once you are logged in, type:

"mathematica" (for X-version) or "math" (for console version).

X-version is more user friendly one.

3) use short references to get accustom with mathematica commands.
To "evaluate" (calculate) a mathematica command you should put cursor at the line with the expression for evaluation and
press <SHIFT> and  <RETURN> keys simultaneously (evaluation == <SHIFT>+<RETURN>).

4) Once you studied basic mathematica commands, you download mathematica notebook file and edit it correspondingly.

5) Use "Save" to save your work and "Quit" to close mathematica session.