NAME
acos, acosf,
acosl —
arc cosine function
LIBRARY
library “libm”
SYNOPSIS
#include
<math.h>
double
acos(double
x);
float
acosf(float
x);
long double
acosl(long
double x);
DESCRIPTION
Theacos(),
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”).