cse 2208 lab 2

#include <bits/stdc++.h>

using namespace std;

double fun(double x)
{
    return (x*x-x-2);
}
double error(double prev, double x0)
{
    return ((x0-prev)/x0);
}
double funmax(int a,int b,int c)
{
    return sqrt(pow((b/a),2)-2*(c/a));
}
void root(double x1,double x2)
{
    double x0,err=1,prev=0;
    int itr=0;

      x0=x1-fun(x1)*(x2-x1)/(fun(x2)-fun(x1));
    while(err>=.0001)
    {
        itr++;
        err=abs(error(prev,x0));

        if(fun(x0)==0)
            break;
        else if(fun(x0)*fun(x1)<0)
            x2=x0;
        else
            x1=x0;

        prev=x0;
        x0=x1-fun(x1)*(x2-x1)/(fun(x2)-fun(x1));

    }
    cout<<x0<<endl;
}
int main()
{

    double x1,x2;
   // cin>>x1>>x2;
   // root(x1,x2);
    double  m=funmax(1,-1,-2);

    for(int i=-m-1;i<=m+1;i++)
    {
       if(fun(i)==0)
       cout<<i<<endl;
        if(fun(i)*fun(i+1)<0)
            root(i,i+1);
    }
    return 0;
}