NAME    [Toc]    [Back]

     acos, acosf - arc cosine functions

SYNOPSIS    [Toc]    [Back]

     #include <math.h>

     double
     acos(double x);

     float
     acosf(float x);

DESCRIPTION    [Toc]    [Back]

     The acos() function computes the principal value of the  arc
cosine of x
     in  the  range  [0,  pi].  The acosf() is a single precision
version of
     acos().

RETURN VALUES    [Toc]    [Back]

     If |x|>1, acos(x) and acosf(x) set the global variable errno
to EDOM.

SEE ALSO    [Toc]    [Back]

     asin(3),   atan(3),   atan2(3),  cos(3),  cosh(3),  math(3),
sin(3), sinh(3),
     tan(3), tanh(3)

OpenBSD      3.6                            May      2,      1991