matlab

EPS=input('EPS=');
xi=input('xi=');
    xf=input('xf=');

while xi>=xf
    xi=input('xi=');
    xf=input('xf=');
end

 he=input('he=');
while (he<0 || xi+he >=xf)
    he=input('he=');
end

xe=xi:he:xf;
np=length(xe);

if(xe(np)<xf)
    xe=[xe xf];
    np=np+1;
end

ye=FCE(xe);

plot(xe,ye,'-r');

xlabel('axa x');
ylabel('axa y');
Title('LABORATOR CN');
grid;

x0=input('xo=');
x1=input('x1=');
x2=input('x2=');

f0=FCE(x0);
f1=FCE(x1);
f2=FCE(x2);

iter=0;
xr=x2;
fr=f2;

while (abs(fr)>EPS)
    iter=iter+1;
    if(x2>x0)
        t=x2;
        x2=x0;
        x0=t;
        t=f2;
        f2=f0;
        f0=t;
    end
    if (x0>x1)
        t=x0;
        x0=x1;
        x1=t;
        t=f0;
        f0=f1;
        f1=t;
    end
    if(x2>x1)
        t=x2;
        x2=x1;
        x1=t;
        t=f2;
        f2=f1;
        f1=t;
    end
    h1=x1-x0;
    if(abs(h1)<EPS)
        fprintf('h1-nul:algoritmul nu converge');
        return;
    end

    h2=x0-x2;
    r=h2/h1;
    d=r*(r+1)*(h1^2);
    if(abs(d)<EPS)
        fprintf('numitor nul pentru a');
        return;
    end
    a=(r*f1-f0*(1+r)+f2)/d;
    b=(f1-f0-a*(h1^2))/h1;
    c=f0;
    delta=b^2-4*a*c;
    if(delta<=0)
        fprintf('radacini complexe sau confundate');
        return;
    end

    if(b>=0)
        d=b+sqrt(delta);
    else
        d=b-sqrt(delta);
    end

    if(abs(d)<EPS)
        fprintf('numitor nul pentru xr');
        return;
    end

    xr=x0-(2*c)/d;
    fr=FCE(xr);
    if(xr>x0)
        x1=xr;
        f1=fr;
    else
        x2=xr;
        f2=fr;
    end
    fprintf('\niter=%g',iter);

     fprintf('\nxr=%g',xr);

      fprintf('\nfr=%g',fr);

  end

   fprintf('\nnumar total iteratii=%g',iter);

    fprintf('\nsolutie xr=%g',xr);

     fprintf('\nvaloare functie fr=%g',fr);