asinh(3M)

NAME
     asinh, acosh, atanh - inverse hyperbolic functions

SYNOPSIS
     #include <math.h>

     double asinh(double x);

     double acosh(double x);

     double atanh(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).

DIAGNOSTICS
     In the diagnostics below, functions in the standard math library libm.a,
     are referred to as -lm versions, those in math library libmx.a are
     referred to as -lmx versions, and those in the the BSD math library
     libm43.a are referred to as -lm43 versions.  The -lm and -lmx versions
     always return the default Quiet NaN and set errno to EDOM when a NaN is
     used as an argument.  A NaN argument usually causes the -lm43 versions to
     return the same argument.  The -lm43 versions never set errno.

     acosh returns the default quiet NaN if the argument is less than 1.  The
     -lm and -lmx versions also set errno to EDOM.

     atanh returns the default quiet NaN if the argument has absolute value
     greater than 1.  The -lm and -lmx versions also set errno to EDOM.

     See matherr(3M) for a description of error handling for -lmx functions.

SEE ALSO
     math(3M), exp(3M), matherr(3M)