function [x_star, elteres] = fixpont_zh1(hiba)

phi = @(x)(0.5*cos(x));  

x(1) = 0;   
it = 0;
elteres = inf;
while (elteres > hiba) 
    it = it + 1;
    x(it+1) = phi(x(it));
    elteres=abs(x(it+1)-x(it));
end
x_star=x(end);

