x=[-180:1:180];
theta=pi*x/180;
a1=1;
a2=0;
o1=pi/2; o2=pi; o3=3*pi/2;
%o1=2*pi/3; o2=4*pi/3; o3=4*pi/3;
t=-a1*sin(theta)-a2*sin(2*theta);
t1=-a1*sin(theta+o1)-a2*sin(2*(theta+o1));
t2=-a1*sin(theta+o2)-a2*sin(2*(theta+o2));
t3=-a1*sin(theta+o3)-a2*sin(2*(theta+o3));
%plot(x,t);
%plot(x,t,'b',x,t1,'r');
plot(x,t,'b',x,t1,'r',x,t2,'g',x,t3,'k');