%syms d r b;
%a=[-d,d,0;r,-1,-20*(0.1*b*(r-1))^0.5;5*(0.1*b*(r-1))^0.5,0,-r];
%a=[-d,d,0;r,-1,0;0,0,-b];
%b=eig(a)

clear
det=10;
b=8/3;
r=28;
a=[-det,det,0;1,-1,-(b*(r-1))^0.5;(b*(r-1))^0.5,(b*(r-1))^0.5,-b];
e=eig(a)