牛顿迭代法求根

# include <iostream>
# include <cmath>
using namespace std;

float Formula(float x)//方程表达式
{
    float y;
    y=x*x*x-2*x-5; //范例方程 
    return y;
}
//求导
float FormulaDao(float x){

   float y;
    y=3*x*x-2; //范例方程的导数 
    return y;
}
void main(){

int n=100,k=0;//最大迭代次数
float x0=1.0;//初始X0的值
float x;
    x=x0;
while(fabs(Formula(x))>0.00001&&k<n)
{
    
    k++;

    x = x - Formula(x) /FormulaDao(x);
}
if(fabs(Formula(x)) < 0.00001){
    cout<<"根植"<<x;
    }
    else 
    cout<<"无根";
    
}