f.cpp

这是用牛顿插值法解方程

#include <iostream>
#include <cmath>
using namespace std;
double function(double n);
double func(double n);
int main()
{  
	double x0;
	cout<<"请输入x0:";
	cin>>x0;
	double s=1.0e-10;
	int N=30;
    int k=1;
	double x1;
	while(k!=N)
	{
      if (func(x0)==0)
	  { cout<<"****";break;}
      else 
	  x1=x0-double (function(x0))/func(x0);
	  cout<<"x1="<<x1<<endl;

	  if(fabs(x1-x0)<s)
	  {  
		cout<<"x="<<x1<<endl;
	    break;
	  }
       
	  else  
	  {k=k+1;
	   x0=x1;
	  }
       if (k==N)
	   {
		 cout<<"失败"<<endl;
	     break;  }
	}

	return 0;
}

double function(double n)
{    
	return 12-3*n+2*cos(n);
}
double func(double n)
{
	return -3-2*sin(n);
}