%%Time specifications:
Fs = 8000;                   % samples per second
dt = 1/Fs;                   % seconds per sample
StopTime = 10;             % seconds
t = (0:dt:StopTime-dt)';     % seconds

%Zad1
omega = 5;

%K(j5)
KJ5 = (3/(65*i +15))
A = abs(KJ5)
fi = angle(KJ5)
K = tf(3, [1 13 40])
u = sin(omega * t);
figure(1)
nyquist(K)

Y1=A*sin(omega*t + fi)
[Y2, Tsim, X] = lsim(K,u,t);  % simulate
figure(2)

hold on
plot(t,Y1, 'b')
hold on
plot(Tsim, Y2, 'r')