%all the graghes are periodic
% X(t)= sin(10pi t ), X(t)= 1/3 sin(30pi t ), X(t)= 1/5 sin(50pi t) 
t=-1:0.0001:1;
y1= sin(10*pi *t );
y2= (1/3)* sin(30*pi *t );
y3=(1/5)* sin(50*pi *t); 
%*********************************
subplot(2,2,1), plot(t,y1,'m');
xlim([-0.1 0.1])
ylim([-1.5 1.5])
xlabel("time (t) for one period"), ylabel("Y1");
title("X1(t)");
%*********************************
yb=y1+y2;
subplot(2,2,2), plot(t,yb,'c');
xlim([-0.1 0.1])
xlabel("time (t) for one period"), ylabel("Yb");
title("Xb(t)=X1(t)+X2(t)");
%*********************************
yc=y1+y2 +y3;
yb=y1+y2;
subplot(2,2,[3,4]), plot(t,yc,'r');
xlim([-0.1 0.1])
xlabel("time (t) for one period"), ylabel("Yc");
title("Xc(t)=X1(t)+X2(t) +X3(t)");
