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 NaN if the argument is less than 1.

          Atanh returns NaN if the argument has absolute value bigger
          than or equal to 1.

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

     AUTHOR
          W. Kahan, Kwok-Choi Ng

     ORIGIN
          MIPS Computer Systems















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