Newton迭代，割线法

#include
#include

double F(double x)
{
	return cos(x) - x;
}

double F_(double x)
{
	return -1 - sin(x);
}

double Newton(double x0,double e,int N)
{
	double x;
	int k = 1;
	do 
	{
		if (F_(x0) == 0)
			break;
		else
			x = x0 - (F(x0) / F_(x0));
		if (fabs(x - x0) < e || fabs(F(x)) < e)
			return x;
		else
			x0 = x;
		k++;
	} while (k <= N);
	return -1;
}

int main()
{
	int N = 100;
	double x0 = 0, e = 0.00001;
	x0 = Newton(x0, e, N);
	printf("%lf", x0);
	getchar();
}

#include
#include

double F(double x)
{
	return cos(x) - x;
}

double X(double x_k1, double x_k0)
{

	return x_k1 - F(x_k1)*((x_k1 - x_k0) / (F(x_k1) - F(x_k0)));
}


double Secant(double x0, double x1, double e)
{
	double temp;
	while (fabs(x0 - x1) > e)
	{
		temp = X(x1, x0);
		x0 = x1;
		x1 = temp;
	}
	return x1;
}

int main()
{
	double x0 = 0, x1 = 1, e = 0.0000001;
	x1 = Secant(x0, x1, e);
	printf("%lf", x1);
	getchar();
}