man3/catanh.3

   1 .\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
   2 .\" Distributed under GPL
   3 .\"
   4 .TH CATANH 3 2002-07-28 "" "Linux Programmer's Manual"
   5 .SH NAME
   6 catanh, catanhf, catanhl \- complex arc tangents hyperbolic
   7 .SH SYNOPSIS
   8 .B #include <complex.h>
   9 .sp
  10 .BI "double complex catanh(double complex " z );
  11 .br
  12 .BI "float complex catanhf(float complex " z );
  13 .br
  14 .BI "long double complex catanhl(long double complex " z );
  15 .sp
  16 Link with \fI\-lm\fP.
  17 .SH DESCRIPTION
  18 The
  19 .BR catanh ()
  20 function calculates the complex atanh(3).
  21 If y = catanh(z), then z = ctanh(y).
  22 The imaginary part of y is chosen in the interval [\-pi/2,pi/2].
  23 .LP
  24 One has catanh(z) = 0.5 * clog((1 + z) / (1 \- z)).
  25 .SH "CONFORMING TO"
  26 C99
  27 .SH "SEE ALSO"
  28 .BR atanh (3),
  29 .BR cabs (3),
  30 .BR cimag (3),
  31 .BR complex (7)