EPS=input('EPS=');
gr=1;
while(gr==1)
xi=input('xi=');
xf=input('xf=');
if(xi>=xf)
    fprintf('xi>xf. Reintroduceti valorile');
    xi=input('xi=');
    xf=input('xf=');
end

he=input('he=');
if((he<=0) || (xi+he>=xf))
    fprintf('Reintroduceti pasul de evaluare he');
    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')
grid

gr=input('Reluare vizualizare si inspectie grafica?DA=1.NU=0');
end



%Metoda Muller


mur=1;
while(mur==1)
x0=input('x0=');
x1=input('x1=');
x2=input('x2=');

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

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

%Aplicare metoda Muller

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('numitorul nul pt xr');
        return
    end

    xr=x0-(2*c)/d;
    fr=FCE(xr);

    if(xr<x0)
        x1=xr;
        f1=fr;
    else
        x2=xr;
        f2=fr;
    end
end
    mur=input('Doriti introducerea altor estimatii DA=1.NU=0');

end

iter
xr
fr

function f=FCE(xe)
f=sin(xe)-xe/2;