# acosh(3) [debian man page]

ACOSH(3) Linux Programmer's Manual ACOSH(3)NAME

acosh, acoshf, acoshl - inverse hyperbolic cosine functionSYNOPSIS

#include <math.h> double acosh(double x); float acoshf(float x); long double acoshl(long double x); Link withFeature Test Macro Requirements for glibc (see feature_test_macros(7)): acosh(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L; or cc-lm.acoshf(), acoshl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L; or cc-std=c99-std=c99DESCRIPTION

The acosh() function calculates 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.CONFORMING TO

C99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD, C89.SEE ALSO

asinh(3), atanh(3), cacosh(3), cosh(3), sinh(3), tanh(3)COLOPHON

This page is part of release 3.44 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. 2010-09-20 ACOSH(3)

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ACOSH(3) Linux Programmer's Manual ACOSH(3)NAME

acosh, acoshf, acoshl - inverse hyperbolic cosine functionSYNOPSIS

#include <math.h> double acosh(double x); float acoshf(float x); long double acoshl(long double x); Link withFeature Test Macro Requirements for glibc (see feature_test_macros(7)): acosh(): _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 500 || /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE acoshf(), acoshl(): _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L || /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE-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). +-----------------------------+---------------+---------+ |Interface | Attribute | Value | +-----------------------------+---------------+---------+ |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 4.15 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/. 2017-09-15 ACOSH(3)