asinh, asinhf, asinhl - inverse hyperbolic sine function
Math library (libm, -lm)
#include <math.h>
double asinh(double x);
float asinhf(float x);
long double asinhl(long double x);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
asinh():
    _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
        || _XOPEN_SOURCE >= 500
        || /* Since glibc 2.19: */ _DEFAULT_SOURCE
        || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
    _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
        || /* Since glibc 2.19: */ _DEFAULT_SOURCE
        || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
These functions calculate the inverse hyperbolic sine of x;
that is the value whose hyperbolic sine is x.
On success, these functions return the inverse hyperbolic sine of
x.
If x is a NaN, a NaN is returned.
If x is +0 (-0), +0 (-0) is returned.
If x is positive infinity (negative infinity), positive
infinity (negative infinity) is returned.
No errors occur.
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value | 
| Thread safety | MT-Safe | 
C11, POSIX.1-2008.
C99, POSIX.1-2001.
The variant returning double also conforms to SVr4,
4.3BSD.