Kotelnikov teoremasini matlab dasturida o’rganish

Kotelnikov teoremasini MATLAB dasturida o’rganish.
fc1=250;
fc2=500;
fc3=750;
fs=2000;
t=0:1/fs:1;
x1=cos(2*pi*fc1*t);
x2=cos(2*pi*fc2*t);
x3=cos(2*pi*fc3*t);
stem(t,x1,'Linewidth',2);
grid on; xlim([0 0.01]);
hold on;
stem(t,x2,'Linewidth',2);stem(t,x3,'Linewidth',2);
hold off;
sound(x1,fs); pause(1);
sound(x2,fs); pause(1);
sound(x3,fs);