alfa=input('alfa=    ');
t=0:0.01:10;
figure(1);
for N=1:4
    subplot(2,2,N);
    x=sin(t);y=sin(N*t+alfa);
    plot(x,y)
end
clear all;
t=0:0.01:10;
N=2;
alfa=[0 pi/3 pi/2 pi];
figure(2);
for p=1:4
    subplot(2,2,p);
    x=sin(t);y=sin(N.*t+alfa(p));
    plot(x,y)
end