4737.sagews

L=matrix([[0,1,0.5],[0.9,0,0],[0,0.8,0]]);L

[0.0 1.0 0.5] [0.9 0.0 0.0] [0.0 0.8 0.0]

-1*L.charpoly()

-x^3 + 0.9*x + 0.36