osf1 man page for acosh

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)