Ill throw in a bit of help.

Here's how you classify linear systems...

Eigenvalues ------------------- Condition ------------------------Type of system

real, opposite sign ------------ ------------------------ saddle

real, positive ----------------- ----- unstable node

real, negative ---------------- ------- stable node

complex, positive real part ----- -------- unstable focus

complex, negative real part ----- -------- stable focus

complex, zero real part --------- -------------- centre

Where det = determinant and tr = trace of a matrix

Sorry im no good at doing latex tables!