ASINH(3M) 1986 ASINH(3M) NNAAMMEE asinh, acosh, atanh - inverse hyperbolic functions SSYYNNOOPPSSIISS ##iinncclluuddee <<mmaatthh..hh>> ddoouubbllee aassiinnhh((xx)) ddoouubbllee xx;; ddoouubbllee aaccoosshh((xx)) ddoouubbllee xx;; ddoouubbllee aattaannhh((xx)) ddoouubbllee xx;; DDEESSCCRRIIPPTTIIOONN These functions compute the designated inverse hyperbolic functions for real arguments. EERRRROORR ((dduuee ttoo RRoouunnddooffff eettcc..)) These functions inherit much of their error from log1p described in exp(3M). On a VAX, acosh is accurate to about 3 _u_l_ps, asinh and atanh to about 2 _u_l_ps. An _u_l_p is one _Unit in the _Last _Place carried. DDIIAAGGNNOOSSTTIICCSS 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. SSEEEE AALLSSOO math(3M), exp(3M), infnan(3M) AAUUTTHHOORR W. Kahan, Kwok-Choi Ng Printed 7/27/90 May 1