| ACOS(3) | Library Functions Manual | ACOS(3) | 
acos, acosf,
  acosl —
#include <math.h>
double
  
  acos(double
    x);
float
  
  acosf(float
    x);
long double
  
  acosl(long
    double x);
acos(), acosf(), and
  acosl() functions compute the principal value of the
  arc cosine of x in the range [0, pi].
acos(x),
  acosf(x), and
  acosl(x) set the global variable
  errno to EDOM.
acos() function conforms to ISO/IEC
  9899:1999 (“ISO C99”).
| January 29, 2013 | NetBSD 9.4 |