#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#define eps 1e-2

/*
* Created by HarvestWu on 2018/07/10.
*/
using namespace std;

//原方程
double f(double x)
{
	return x*x*x + x - 1;
}
//导函数
double f1(double x)
{
	return 3*x*x + 1;
}

//平分法
double binary(double a, double b)
{
	double x;
	do
	{
		x = (a + b) / 2;
		if (f(a)*f(x) > 0)
			a = x;
		else b = x;

	} while (fabs(f(x)) > eps);
	return x;

}

//试位法
double false_pos(double a, double b)
{
	double x;
	do
	{
		x = (a*f(b) - b*f(a)) / (f(b) - f(a));
		if (f(x)*f(a) > 0)
			a = x;
		else b = x;
	} while (fabs(f(x))>eps);
	return x;
}

//牛顿法
double newton(double x)
{
	do
	{
		x = x - f(x) / f1(x);
	} while (fabs(f(x)) > eps);
	return x;
}

int main()
{
	double a, b;
	a = -10.0;
	b = 10.0;
	printf("%lf\n", binary(a, b));
	printf("%lf\n", false_pos(a, b));
	printf("%lf\n", newton(3));
	return 0;
}