A = [3 0;0 -2];
B = [3 0;0 -2];
C = [-1 1;1 -1];
D=0;
x0 = [1 -1];
poles = eig(A) % You have unstable poles (pole=3)
% open-loop response:
t = (0:0.01:5)';
u = [sin(t) sin(t)] % create your input signals
sys = ss(A,B,C,D);
[y,t,x] = lsim(sys,u,t,x0);
plot(t,y)
