Need help with outputting data in exact intervals.

[TimeWalker]

Here's the code that increases x value by 0.01 increment and outputs: x, placeholder for initial x+t and how many loop cycles it took to find a solution to the equation in function f1() in intervals for temp (0.5 ; 1.0)U(1.0 ; 1.5).

#include <iostream>

#include <cstdlib>

#include <cmath>

#include <iomanip>

using namespace std;



double f1(double z){

return pow(z,4)+3*pow(z,3)+pow(z,2)-3*z-2;

}



int main()

{

double temp = 0.0;

double init = 0.104;

double x = 0.0;

int k = 0;

double i = 0.505 - init;

double eps = 0.001;



while ( (init + i) < 1.5  )

{	

	x = init + i;

	

	if(x != 1)

	{

		k=0;



		while (fabs(f1(x)) > eps)

		{

			x=4*x*(1-x);

			k++;

		}



		temp = init + i;

		cout << setprecision(4)  << x << " " << temp<< " " << k << endl;	

	}



	i += 0.01;

}



return 0;

}

But the problem is - as soon as initial x+t hits the value of 1.0 square iterator loop messes :

while (fabs(f1(x)) > eps)

		{

			x=4*x*(1-x);

			k++;

		}

it all up and x becomes -inf, cause x value can't be 1 according to the rules. i'm not allowed to change x=4*x*(1-x) formula. Need the program to output x, temp, and k in the intervals stated above. I understand that i somehow have to adjust this part (fabs(f1(x)) > eps) and then adjust the intervals, but i'm unable to come up with a proper solution.

Thanx in advance!