/* --------------------------------- */
/* save as fb.h                      */
/* --------------------------------- */
double f(
double x,
double y,
double z)
{
 return(     (x*x*x*y*y*z-x*y+z) );
}
char  feq[] = "x**3*y**2*z-x*y+z";
/* --------------------------------- */
double f_x(
double x,
double y,
double z)
{
 return(       (-y+3*x*x*y*y*z) );
}
char Dfeq_x[] = "-y+3*x**2*y**2*z";
/* --------------------------------- */
double f_y(
double x,
double y,
double z)
{
 return(        (-x+2*x*x*x*y*z)  );
}
char Dfeq_y[] = "-x+2*x**3*y*z";
/* --------------------------------- */
double f_z(
double x,
double y,
double z)
{
 return(        (1+pow(x,3)*y*y)  );
}
char Dfeq_z[] = "1+x**3*y**2";
/* --------------------------------- */
double f_xx(
double x,
double y,
double z)
{
 return(         (6*x*y*y*z ) );
}
char Dfeq_xx[] = "6*x*y**2*z";
/* --------------------------------- */
double f_yy(
double x,
double y,
double z)
{
 return(         (2*pow(x,3)*z));
}
char Dfeq_yy[] = "2*x**3*z";
/* --------------------------------- */
/* --------------------------------- */
double f_zz(
double x,
double y,
double z)
{
 return(         (0));
}
char Dfeq_zz[] = "0";
/* --------------------------------- */