atanh(3m) [bsd man page]

ASINH(3M)																 ASINH(3M)

NAME

       asinh, acosh, atanh - inverse hyperbolic functions

SYNOPSIS

       #include <math.h>

       double asinh(x)
       double x;

       double acosh(x)
       double x;

       double atanh(x)
       double x;

DESCRIPTION

       These functions compute the designated inverse hyperbolic functions for real arguments.

ERROR (due to Roundoff etc.)
       These  functions inherit much of their error from log1p described in exp(3M).  On a VAX, acosh is accurate to about 3 ulps, asinh and atanh
       to about 2 ulps.  An ulp is one Unit in the Last Place carried.

DIAGNOSTICS

       Acosh returns the reserved operand on a VAX if the argument is less than 1.

       Atanh returns the reserved operand on a VAX if the argument has absolute value bigger than or equal to 1.

SEE ALSO

       math(3M), exp(3M), infnan(3M)

AUTHOR

       W. Kahan, Kwok-Choi Ng

4.3 Berkeley Distribution					   May 12, 1986 							 ASINH(3M)

asinh(3)						     Library Functions Manual							  asinh(3)

NAME

       asinh, acosh, atanh - Compute inverse hyperbolic functions

LIBRARY

       Math Library (libm.a)

SYNOPSIS

       #include <math.h>

       double  asinh  (double x); float  asinhf (float	x); long double asinhl	   (long double x); double acosh  (double x); float  acoshf (float
       x); long double acoshl	  (long double x); double atanh  (double x); float  atanhf (float  x); long double atanhl     (long double x);

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       asinh():  XPG4-UNIX

       acosh():  XPG4-UNIX

       atanh():  XPG4-UNIX

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

DESCRIPTION

       The asinh(), asinhf(), and asinhl() functions return the hyperbolic arc sine of x, in the range [-infinity,  +infinity]	where  asinh(x)  =
       ln(x + sqrt(x**2 + 1)).	The asinh() function is the inverse function of sinh() where asinh(sinh(x)) = x.

       The  acosh(),  acoshf(),  and acoshl() functions return the hyperbolic arc cosine of x, in the range [1, +infinity] where acosh(x) = ln(x +
       sqrt(x**2 - 1)).  The acosh() function is the inverse function of cosh() where acosh(cosh(x)) = |x|.

       The atanh(), atanhf()  and atanhl() functions return the hyperbolic arc tangent of x, in the range (-1, 1).  The atanh()  function  is  the
       inverse function of tanh() where atanh(tanh(x)) = x.

       The following table describes function behavior in response to exceptional arguments:

       ---------------------------------------------------
       Function   Exceptional Argument	 Routine Behavior
       ---------------------------------------------------
       asinh()	  None			 N/A
       asinhf()   None			 N/A
       asinhl()   None			 N/A
       acosh()	  x<1			 Invalid argument
       acoshf()   x<1			 Invalid argument
       acoshl()   x<1			 Invalid argument
       atanh()	  x>1 or x=1		 Invalid argument
       atanhf()   x>1 or x=1		 Invalid argument
       atanhl()   x>1 or x=1		 Invalid argument
       ---------------------------------------------------
       delim off

																	  asinh(3)