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.
SEE ALSO
asin(3),
atan(3),
atan2(3),
cos(3),
cosh(3),
math(3),
sin(3),
sinh(3),
tan(3),
tanh(3)
STANDARDS
The
acos() function conforms to
ISO/IEC
9899:1999 (“ISO C99”).