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   coshl    ( 3 )

функция гиперболического косинуса (hyperbolic cosine function)

Имя (Name)

cosh, coshf, coshl - hyperbolic cosine function


Синопсис (Synopsis)

#include <math.h>

double cosh(double x); float coshf(float x); long double coshl(long double x);

Link with -lm.

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

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


Описание (Description)

These functions return the hyperbolic cosine of x, which is defined mathematically as:

cosh(x) = (exp(x) + exp(-x)) / 2


Возвращаемое значение (Return value)

On success, these functions return the hyperbolic cosine of x.

If x is a NaN, a NaN is returned.

If x is +0 or -0, 1 is returned.

If x is positive infinity or negative infinity, positive infinity is returned.

If the result overflows, a range error occurs, and the functions return +HUGE_VAL, +HUGE_VALF, or +HUGE_VALL, respectively.


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:

Range error: result overflow errno is set to ERANGE. An overflow floating-point exception (FE_OVERFLOW) is raised.


Атрибуты (Attributes)

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

┌──────────────────────────────────────┬───────────────┬─────────┐ │Interface Attribute Value │ ├──────────────────────────────────────┼───────────────┼─────────┤ │cosh(), coshf(), coshl() │ Thread safety │ MT-Safe │ └──────────────────────────────────────┴───────────────┴─────────┘


Стандарты (Conforming to)

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

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


Ошибки (баги) (Bugs)

In glibc version 2.3.4 and earlier, an overflow floating-point (FE_OVERFLOW) exception is not raised when an overflow occurs.


Смотри также (See also)

acosh(3), asinh(3), atanh(3), ccos(3), sinh(3), tanh(3)