# include <stdio.h>

int main ( )
{
  float a;
  float b;
  float c;
  float d;
  float dx;
  float dy;
  float fxy;
  int i;
  int j;
  int m;
  int n;
  float x;
  float y;

  a = -10.0;
  b = +10.0;

  c = -10.0;
  d = +10.0;

  m = 5;
  n = 5;

  dx = ( b - a ) / ( m - 1 );
  dy = ( d - c ) / ( n - 1 );

  for ( i = 0; i < m; i++ )
  {
    x = a + i * dx;
    for ( j = 0; j < n; j++ )
    {
      y = b + j * dy;
      fxy = x * x + y * y + 2 * x + 8 * y;

      printf ( "F(%f,%f) = %f\n", x, y, fxy );
    }
  }

  return 0;
}