clear all;
clc;
a=input('a = ');
b=input('b = ');
e=input('e = ');
while(abs(b-a)>e)
    x=(a+b)/2;
    f1=a^3-a-1;
    f2=b^3-b-1;
    f3=x^3-x-1;
    if(f1*f3==0)
        disp('x is the root');
    else if(f1*f3<0)
            b=x;
        else
            a=x;
        end
        disp(x);
    end
end