atanh(3m) [sunos man page]

atanh(3M)						  Mathematical Library Functions						 atanh(3M)

NAME

       atanh, atanhf, atanhl - inverse hyperbolic tangent functions

SYNOPSIS

       cc [ flag... ] file... -lm [ library... ]
       #include <math.h>

       double atanh(double x);

       float atanhf(float x);

       long double atanhl(long double x);

DESCRIPTION

       These functions compute the inverse hyperbolic tangent of their argument x.

RETURN VALUES

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

       If  x  is  +-1,	a  pole error occurs and atanh(), atanhf(), and atanhl() return the value of the macro HUGE_VAL, HUGE_VALF, and HUGE_VALL,
       respectively, with the same sign as the correct value of the function.

       For finite |x| > 1, a domain error occurs and a NaN is returned.

       If x is NaN, NaN is returned.

       If x is +0, x is returned.

       If x is +Inf, a domain error occurs and a NaN is returned.

       For exceptional cases, matherr(3M) tabulates the values to be returned by atanh() as specified by SVID3 and XPG3.

ERRORS

       These functions will fail if:

       Domain Error    The x argument is finite and not in the range [-1,1], or is +-Inf.

		       If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, the invalid floating-point exception is raised.

		       The atanh() function sets errno to EDOM if the absolute value of x is greater than 1.0.

       Pole Error      The x argument is +-1.

		       If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, then the divide-by-zero floating-point exception
		       is raised.

		       The atanh() function sets errno to ERANGE if the absolute value of x is equal to 1.0.

USAGE

       An  application	wanting  to  check  for  exceptions should call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if
       fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception  has  been  raised.  An  application  should
       either examine the return value or check the floating point exception flags to detect exceptions.

       An  application	can  also  set errno to 0 before calling atanh(). On return, if errno is non-zero, an error has occurred. The atanhf() and
       atanhl() functions do not set errno.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       feclearexcept(3M), fetestexcept(3M), math.h(3HEAD), matherr(3M), tanh(3M), attributes(5), standards(5)

SunOS 5.10							    1 Sep 2002								 atanh(3M)

Check Out this Related Man Page

ATANH(3)						     Linux Programmer's Manual							  ATANH(3)

NAME

       atanh, atanhf, atanhl - inverse hyperbolic tangent function

SYNOPSIS

       #include <math.h>

       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)):

       atanh(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 || _ISOC99_SOURCE; or cc -std=c99
       atanhf(), atanhl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99

DESCRIPTION

       The atanh() function calculates the inverse hyperbolic tangent of x; that is the value whose hyperbolic tangent is x.

RETURN VALUE

       On success, these functions return the inverse hyperbolic tangent of x.

       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.

ERRORS

       See 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 TO

       C99, POSIX.1-2001.  The variant returning double also conforms to SVr4, 4.3BSD, C89.

BUGS

       For a pole error, errno is set to EDOM; POSIX.1 says it should be set to ERANGE.

SEE ALSO

       acosh(3), asinh(3), catanh(3), cosh(3), sinh(3), tanh(3)

COLOPHON

       This page is part of release 3.25 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/.

								    2008-08-05								  ATANH(3)

Linux and UNIX Man Pages

atanh(3m) [sunos man page]

Check Out this Related Man Page