// -y＾2 * z＾2 - y＾2 + 24*y*z - z＾2 -13 = 0
// -x＾2 * z＾2 - x＾2 + 24*x*z - z＾2 -13 = 0
// -x＾2 * y＾2 - x＾2 + 24*x*y - y＾2 -13 = 0
#include <stdio.h>

double f1(double x, double y, double z)
{
        return -y*y * z*z - y*y + 24*y*z - z*z -13;
}
double f2(double x, double y, double z)
{
        return -x*x * z*z - x*x + 24*x*z - z*z -13;
}
double f3(double x, double y, double z)
{
        return -x*x * y*y - x*x + 24*x*y - y*y -13;
}

int main()
{
	double x = 0.77954804507915753664;
	double y = 0.77954804507915753664;
	double z = 0.77954804507915753664;

	printf("f1=%.20f\n", f1(x,y,z));
	printf("f2=%.20f\n", f2(x,y,z));
	printf("f3=%.20f\n", f3(x,y,z));
	return 0;
}