+{-# LANGUAGE CPP, DeriveDataTypeable #-}
+
-----------------------------------------------------------------------------
-- |
-- Module : Data.Complex
asinh z = log (z + sqrt (1+z*z))
acosh z = log (z + (z+1) * sqrt ((z-1)/(z+1)))
- atanh z = log ((1+z) / sqrt (1-z*z))
+ atanh z = 0.5 * log ((1.0+z) / (1.0-z))