ASINH(3) Library Functions Manual ASINH(3)

NAME

asinh asinhf asinhl — inverse hyperbolic sine functions

SYNOPSIS

#include <math.h>

double asinh(double x);
float asinhf(float x);
long double asinhl(long double x);

DESCRIPTION

[CX] 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.1-2008 defers to the ISO C standard.

These functions shall compute the inverse hyperbolic sine 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.

RETURN VALUE

Upon successful completion, these functions shall return the inverse hyperbolic sine of their argument.

[MX] If x is NaN, a NaN shall be returned.

If x is ±0, or ±Inf, x shall be returned.

If x is subnormal, a range error may occur [MXX] and x should be returned.

[MX] If x is not returned, asinh (), asinhf (), and asinhl () shall return an implementation-defined value no greater in magnitude than DBL_MIN, FLT_MIN, and LDBL_MIN, respectively.

ERRORS

These functions may fail if:

Range Error: [MX] The value of x is subnormal.
If the integer expression ( math_errhandling & MATH_ERRNO) is non-zero, then errno shall be set to [ERANGE]. If the integer expression ( math_errhandling & MATH_ERREXCEPT) is non-zero, then the underflow floating-point exception shall be raised.

The following sections are informative.

EXAMPLES

None.

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.