NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | ATTRIBUTES | SEE ALSO | STANDARDS
#include <math.h>double acos(double x);
The acos function computes the principal value of the arc cosine of x. A domain error occurs for arguments not in the range [-1, +1]. For a discussion of errors due to rounding off, see math(3M).
The acos function returns the arc cosine in the range [0, Pi] radians. If | x | > 1, errno is set to EDOM and a system-dependent notification is performed.
See attributes(5) for descriptions of the following attributes:
ATTRIBUTE TYPE | ATTRIBUTE VALUE |
---|---|
Interface Stability | Evolving |
The acos function conforms to ANSI-C.
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | ATTRIBUTES | SEE ALSO | STANDARDS