The
cacosh()
function calculates the complex arc hyperpolic cosine of
z.
If y = cacosh(z), then z = ccosh(y).
The imaginary part of
y
is chosen in the interval [-pi,pi].
The real part of
y
is chosen nonnegative.

One has:

cacosh(z) = (0.5) * clog((1 + z) / (1 - z))

VERSIONS

These functions first appeared in glibc in version 2.1.

This page is part of release 3.27 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/.