clear;
close;
g1=0:0.1:4;

t_D=0.5;

b1=20.8+0.696/t_D;
b2=0.696/t_D;
b3=20.8+0.696/t_D;
b4=0.696/t_D;

a0=1;
a1=(b1+b2+b3+b4);
a2=(b1*b2+b1*b3+b1*b4+b2*b3+b2*b4+b3*b4)-g1*b1*b2;
a3=b1*b2*b3+b1*b2*b4+b2*b3*b4+b1*b3*b4-g1*b1*b2*b3-g1*b1*b2*b4;

y1=1-(a1*a2.*a3-a3.*a3)./(a1*a1*b1*b2*b3*b4);
y2=1-g1;

plot(g1,y1,'b',g1,y2,'r');
axis([0 4 -20 2]);
grid on;
xlabel('g12');
ylabel('g14g32');