ACOS(3) Library Functions Manual ACOS(3)
NAME
acos, acosfarc cosine function
LIBRARY
Math Library (libm, -lm)
SYNOPSIS
#include <math.h>
double
acos(double x);
float
acosf(float x);
DESCRIPTION
The acos() and acosf() functions compute the principal value of the arc cosine of x in the range [0, π].
RETURN VALUES
If |x|>1, acos(x) and acosf(x) set the global variable errno to EDOM.
SEE ALSO
STANDARDS
The acos() function conforms to ANSI X3.159-1989 (“ANSI C”).