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   acoshl    ( 3 )

функция обратного гиперболического косинуса (inverse hyperbolic cosine function)

Имя (Name)

acosh, acoshf, acoshl - inverse hyperbolic cosine function

Синопсис (Synopsis)

#include <math.h>

double acosh(double x); float acoshf(float x); long double acoshl(long double x);

Link with -lm.

Feature 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 <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

acoshf(), acoshl(): _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L || /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* Glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE


Описание (Description)

These functions calculate the inverse hyperbolic cosine of x;
       that is the value whose hyperbolic cosine is x.

Возвращаемое значение (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.


Ошибки (Error)

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.


Атрибуты (Attributes)

For an explanation of the terms used in this section, see
       attributes(7).

┌──────────────────────────────────────┬───────────────┬─────────┐ │Interface Attribute Value │ ├──────────────────────────────────────┼───────────────┼─────────┤ │acosh(), acoshf(), acoshl() │ Thread safety │ MT-Safe │ └──────────────────────────────────────┴───────────────┴─────────┘


Стандарты (Conforming to)

C99, POSIX.1-2001, POSIX.1-2008.

The variant returning double also conforms to SVr4, 4.3BSD.


Смотри также (See also)

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