#include "iostream.h"
#include "math.h"
const double m=2.7184826;
double f(double x,double e);
double fr(double x,double e);

void main()
{
	double x0,x1,e,q;
	cout<<"請輸入x0值:";
	cin>>x0;
	cout<<"輸入誤差限e:";
	cin>>e;
	q=fr(x0,e);

	//x1=f(x0)+q/(1-q)*(f(x0)-x0);
	do
	{
		x0=x1;
		cout<<"中間結果為"<<x1<<endl;
		//q=fr(x0);
	    x1=f(x0,e)+q/(1-q)*(f(x0,e)-x0);
        cout<<"中間結果為"<<x1<<endl;
	}while(fabs(x1-x0)>=e);
	cout<<"方程結果為:"<<x1;
	cout<<endl;
}
double f(double x,double e)
{
	return pow(e,-x);
}

double fr(double x,double e)
{
	return -1*pow(e,-x);
	//double y1;
	//x=log(x)+89.62092;
	//y1=1/3*exp(-2/3*log10(x));//y1=pow(x/3,-2/3);
	//return y1;
}