i0 = 1  ;
V  = 10 ;
R  = 1  ;
L  = 2  ;
T  = 10 ;
N  = 30 ;
[t,i,e] = circuito(i0,V,R,L,T,N);
hold off ;
plot(t,i,'.-b');
hold on ;
plot(t,e,'-r');
legend('approssimata','esatta');
