|ATANH(3)||Linux Programmer's Manual||ATANH(3)|
double atanh(double x); float atanhf(float x); long double atanhl(long double x);Link with -lm.
_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
If x is a NaN, a NaN is returned.
If x is +0 (-0), +0 (-0) is returned.
If x is +1 or -1, a pole error occurs, and the functions return HUGE_VAL, HUGE_VALF, or HUGE_VALL, respectively, with the mathematically correct sign.
If the absolute value of x is greater than 1, a domain error occurs, and a NaN is returned.
The following errors can occur:
- Domain error: x less than -1 or greater than +1
- errno is set to EDOM. An invalid floating-point exception (FE_INVALID) is raised.
- Pole error: x is +1 or -1
- errno is set to ERANGE (but see BUGS). A divide-by-zero floating-point exception (FE_DIVBYZERO) is raised.
|atanh (), atanhf (), atanhl ()||Thread safety||MT-Safe|
The variant returning double also conforms to SVr4, 4.3BSD.