clear all
F=@(t)(normcdf(t,500,100)-normcdf(0,500,100));
f=@(x,y)0.02./x-(1.0586*F(8655.0*y-5769.2)+0.2*1.0386*F(8821.7*y-5769.2));
ezplot(f,[0.006,0.06,0,1])