clc;
clear;
fp=500e3;
f=10e3;
li_cykli=5;
t=0:1/fp:li_cykli*1/f;
x=cos(2*pi*f*t);
fp1=30e3;
t1=0:1/fp1:li_cykli*1/f;
x1=cos(2*pi*f*t1);
fp2=50e3;
t2=0:1/fp2:li_cykli*1/f;
x2=cos(2*pi*f*t2);
plot(t1,x1);
hold on;
stem(t1,x1);
figure;
plot(t,x);
hold on;
stem(t2,x2);