11F牛顿迭代法



#include<stdio.h>
#include<math.h>

int main()
{
    double solut(double,double,double,double );
    double a,b,c,d;
    scanf("%lf%lf%lf%lf",&a,&b,&c,&d);
    printf("%.2f",solut(a,b,c,d));;
    return 0;
}

double solut(double a,double b,double c,double d)
{
    double x=1,x0;
    do
    {
        x0=x;
        x=x0-(((a*x+b)*x+c)*x+d)/((3*a*x+2*b)*x+c);
    }
    while(fabs(x-x0)>=1e-5);
    return x;
}