TO-l2

 clc;
 clear;
 xm=-10;
 xM=10;
% xm=x1;
 %xM=x2-d/2;
 s=(sqrt(5)-1)/2;
 x1=xm+(1-s)*(xM-xm);
 x2=xm+s*(xM-xm);
 E=0.000001;
 f1=f(x1);
 f2=f(x2);
 while abs(xM-xm)>=E
 if(f1<f2)
     xM=x2;
     x2=x1;
     x1=xm+(1-s)*(xM-xm);
     f1=f(x1);
     f2=f(x2);
 else
     if(f1>f2)
         xm=x1;
         x1=x2;
         x2=xm+s*(xM-xm);
         f1=f(x1);
         f2=f(x2);
     else
         if(f1==f1)
             xm=x1;
             xM=x2;
             x1=xm+(1-s)*(xM-xm);
                x2=xm+s*(xM-xm);
                f1=f(x1);
                f2=f(x2);
         end
     end
 end
 end

 xmin=(xm+xM)/2;
 xmin