n=5;
alpha=2.2;
A=zeros(n,n);
for i=1:n-1
    A(i,i)=2+alpha;
    A(i+1,i)=-1;
    A(i,i+1)=-1;
end
A(n,n)=2+alpha;
[z,theta]=compito(n,alpha);
b=zeros(n,1);b(1)=theta;
x=[z;1];
A*x-b