[MEGOLDVA]Arkusz tangens hiba Perl-ben (?)

gyanítom, hogy ez a baj: http://perldoc.perl.org/functions/atan2.html
A Perles megoldásban a paraméterek sorrendje Y, X

stp@T61:~$ 
stp@T61:~$ cat hup_atan2.c 
#include "stdio.h"
#include "math.h"

#define N1 27278059051902.5
#define N2 29996016632198.0

void main( void )
{
  printf("The arc tangent for %lf and %lf is %lf\n", N1, N2, atan2(N1, N2) );
}

stp@T61:~$ gcc hup_atan2.c 
stp@T61:~$ ./a.out 
The arc tangent for 27278059051902.500000 and 29996016632198.000000 is 0.737978
stp@T61:~$ 

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atan2
     double atan2 (      double y,      double x );
long double atan2 ( long double y, long double x );
      float atan2 (       float y,       float x );

Compute arc tangent with two parameters
Returns the principal value of the arc tangent of y/x, expressed in radians.