ACOS(3) |
Library Functions Manual |
ACOS(3) |
NAME
acos, acosf, acosl — arc cosine function
LIBRARY
Math Library (libm, -lm)
SYNOPSIS
#include <math.h>
double
acos(double x);
float
acosf(float x);
long double
acosl(long double x);
DESCRIPTION
The acos(), acosf(), and acosl() functions compute the principal value of the arc cosine of x in the range [0, pi].
RETURN VALUES
If |x|>1, acos(x), acosf(x), and acosl(x) set the global variable errno to EDOM.
STANDARDS
The acos() function conforms to ISO/IEC 9899:1999 (“ISO C99”).