функции обратного гиперболического косинуса (inverse hyperbolic cosine functions)
Пролог (Prolog)
This manual page is part of the POSIX Programmer's Manual. The
Linux implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
Имя (Name)
acosh, acoshf, acoshl — inverse hyperbolic cosine functions
Синопсис (Synopsis)
#include <math.h>
double acosh(double x);
float acoshf(float x);
long double acoshl(long double x);
Описание (Description)
The functionality described on this reference page is aligned
with the ISO C standard. Any conflict between the requirements
described here and the ISO C standard is unintentional. This
volume of POSIX.1‐2017 defers to the ISO C standard.
These functions shall compute the inverse hyperbolic cosine of
their argument x.
An application wishing to check for error situations should set
errno to zero and call feclearexcept(FE_ALL_EXCEPT) before
calling these functions. On return, if errno is non-zero or
fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW |
FE_UNDERFLOW) is non-zero, an error has occurred.
Возвращаемое значение (Return value)
Upon successful completion, these functions shall return the
inverse hyperbolic cosine of their argument.
For finite values of x < 1, a domain error shall occur, and
either a NaN (if supported), or an implementation-defined value
shall be returned.
If x is NaN, a NaN shall be returned.
If x is +1, +0 shall be returned.
If x is +Inf, +Inf shall be returned.
If x is -Inf, a domain error shall occur, and a NaN shall be
returned.
Ошибки (Error)
These functions shall fail if:
Domain Error
The x argument is finite and less than +1.0, or is
-Inf.
If the integer expression (math_errhandling &
MATH_ERRNO) is non-zero, then errno shall be set to
[EDOM]. If the integer expression (math_errhandling
& MATH_ERREXCEPT) is non-zero, then the invalid
floating-point exception shall be raised.
The following sections are informative.
Примеры (Examples)
None.
Использование в приложениях (Application usage)
On error, the expressions (math_errhandling & MATH_ERRNO) and
(math_errhandling & MATH_ERREXCEPT) are independent of each
other, but at least one of them must be non-zero.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
None.
Смотри также (See also)
cosh(3p), feclearexcept(3p), fetestexcept(3p)
The Base Definitions volume of POSIX.1‐2017, Section 4.20,
Treatment of Error Conditions for Mathematical Functions,
math.h(0p)
