clear;
a=1;b=1;c=0.3;d=100;
x=1:100;
y=0.3.*(d*d-x.*x)./(2.*x-1)+(100*100-x.*x)./(2.*x-1);
z=0.3+x.*x;
f=0.23.*x.*x+(1-0.23).*(0.3.*(d.*d-x.*x))./(2.*x-1)+(d.*d-(x-1).*(x-1))./(2.*x-1);
plot(y,'-.');
hold on;
plot(z,'.r');
hold on;
plot(f,'*g');
xlabel('D');ylabel('E'),hold off
axis([0 100 0 14000]);