|ATANH(3)||Linux Programmer's Manual||ATANH(3)|
NAMEatanh, atanhf, atanhl - inverse hyperbolic tangent function
double atanh(double x );
float atanhf(float x );
long double atanhl(long double x );
Link with -lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;or cc -std=c99
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;or cc -std=c99
DESCRIPTIONThe atanh() function calculates the inverse hyperbolic tangent of x; that is the value whose hyperbolic tangent is x.
RETURN VALUEOn success, these functions return the inverse hyperbolic tangent of x.
ERRORSSee math_error(7) for information on how to determine whether an error has occurred when calling these functions.
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.
CONFORMING TOC99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD, C89.
BUGSIn glibc 2.9 and earlier, when a pole error occurs, errno as set to EDOM instead of the POSIX-mandated ERANGE. Since version 2.10, glibc does the right thing.
SEE ALSOacosh(3), asinh(3), catanh(3), cosh(3), sinh(3), tanh(3)
COLOPHONThis page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.