|ACOSH(3)||Linux Programmer's Manual||ACOSH(3)|
NAME¶acosh, acoshf, acoshl - inverse hyperbolic cosine function
double acosh(double x); float acoshf(float x); long double acoshl(long double x);Link with -lm.
DESCRIPTION¶These functions calculate the inverse hyperbolic cosine of x; that is the value whose hyperbolic cosine is x.
RETURN VALUE¶On success, these functions return the inverse hyperbolic cosine of x.
If x is a NaN, a NaN is returned.
If x is +1, +0 is returned.
If x is positive infinity, positive infinity is returned.
If x is less than 1, a domain error occurs, and the functions return a NaN.
ERRORS¶See math_error(7) for information on how to determine whether an error has occurred when calling these functions.
The following errors can occur:
- Domain error: x is less than 1
- errno is set to EDOM. An invalid floating-point exception (FE_INVALID) is raised.
ATTRIBUTES¶For an explanation of the terms used in this section, see attributes(7).
|acosh (), acoshf (), acoshl ()||Thread safety||MT-Safe|
CONFORMING TO¶C99, POSIX.1-2001, POSIX.1-2008.
The variant returning double also conforms to SVr4, 4.3BSD.
SEE ALSO¶asinh(3), atanh(3), cacosh(3), cosh(3), sinh(3), tanh(3)
COLOPHON¶This page is part of release 5.10 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.