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)
