NAME
       catanh, catanhf, catanhl - complex arc tangents hyperbolic
SYNOPSIS
       #include <complex.h>
       double complex catanh(double complex z);
       float complex catanhf(float complex z);
       long double complex catanhl(long double complex z);
       Link with -lm.
DESCRIPTION
       The  catanh() function calculates the complex arc hyperbolic tangent of
       z.  If y = catanh(z), then z = ctanh(y).  The imaginary part  of  y  is
       chosen in the interval [-pi/2,pi/2].
       One has:
           catanh(z) = 0.5 * clog((1 + z) / (1 - z))
VERSIONS
       These functions first appeared in glibc in version 2.1.
CONFORMING TO
       C99.
SEE ALSO
       atanh(3), cabs(3), cimag(3), complex(7)
COLOPHON
       This  page  is  part of release 3.24 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.
                                  2008-08-11