Find all roots

package findallroots1;

import java.util.ArrayList;
import java.util.List;

public class FINDALLROOTS1
{
    //public static double ESP = 0.001;
    public static double F(double x)
    {
        double result = (Math.pow(x, 2))-(4*x)-10; //x2-4x-10=0
        return result;
    }
    public static double F(double a,double b,double c,double x)
    {
        double result = (a*Math.pow(x, 2))+(b*x)+c; //x2-4x-10=0
        return result;
    }
    public static double sumAll(List<Double> list)
    {
        double sum=0;
        for(int i=0;i<list.size();i++)
        {
           sum=sum+list.get(i);
        }
        return sum;
    }
    public static double maximumPoint(double a,double b,double c)
    {
        double x = Math.ceil(Math.sqrt(Math.pow((b/a),2)-(2*(c/a))));
        return x;
    }
    public static boolean checkSign(double x)
    {
        if(x<0)
        {
            return false;
        }
        return true;
    }
    public static void bisection(double x1,double x2)
    {
        //x2-4x-10
        int i = 1;
        double x0;
        double f2,f0,f1,t;
        double ESP = 0.001;

        System.out.println("\n__________________________________________________________________\n");
        System.out.println("\niteration\t x1\t       x2\t x0\t   f1\t   f2\t   f0");
        System.out.println("\n___________________________________________________________________\n");
        do
        {
            x0=(x1+x2)/2;
            f1=F(x1);
            f2=F(x2);
            f0=F(x0);
            System.out.println("\n"+" "+i+" "+x1+" "+x2+" "+x0+" "+f1+" "+f2+" "+f0);
            if(f1*f0<0)
            {
                x2=x0;
            }
            else
            {
                x1=x0;
            }
            i++;
        }
        while(Math.abs(f0)>ESP);
        System.out.println("\n__________________________________________________________\n");
        System.out.println("\n\nRoot = "+x0);
    }
    public static void main(String[] args)
    {
        // a=1,b=-4,c=-10
        double initialStart=maximumPoint(1,-4,-10);
        double initialEnd=-maximumPoint(1,-4,-10);
        double stepSize = 1;
        //create a chart of x and y=F(x)
        List<Double> listX =new ArrayList();
        List<Double> listFX = new ArrayList();
        for(double i=initialEnd;i<=initialStart;i=i+stepSize)
        {
            double X = i;
            double FX = F(X);
            listX.add(X);
            listFX.add(FX);
        }
        //now find each two points that bracket root
        List<Double> listBracket = new ArrayList();
        for(int i=0;i<listX.size()-1;i++)
        {
            boolean previous = checkSign(listFX.get(i));
            boolean next = checkSign(listFX.get(i+1));
            if(previous!=next)
            {
                listBracket.add(listX.get(i));
                listBracket.add(listX.get(i+1));
            }
        }
        //finally do bisection between them
        for(int i=0;i<listBracket.size();i=i+2)
        {
            bisection(listBracket.get(i),listBracket.get(i+1));
        }
    }

}