## Inverse Complex Hyperbolic Functions

Function: gsl_complex gsl_complex_arcsinh (gsl_complex z)
This function returns the complex hyperbolic arcsine of the complex number z, @math{\arcsinh(z)}. The branch cuts are on the imaginary axis, below @math{-i} and above @math{i}.

Function: gsl_complex gsl_complex_arccosh (gsl_complex z)
This function returns the complex hyperbolic arccosine of the complex number z, @math{\arccosh(z)}. The branch cut is on the real axis, less than @math{1}.

Function: gsl_complex gsl_complex_arccosh_real (double z)
This function returns the complex hyperbolic arccosine of the real number z, @math{\arccosh(z)}.

Function: gsl_complex gsl_complex_arctanh (gsl_complex z)
This function returns the complex hyperbolic arctangent of the complex number z, @math{\arctanh(z)}. The branch cuts are on the real axis, less than @math{-1} and greater than @math{1}.

Function: gsl_complex gsl_complex_arctanh_real (double z)
This function returns the complex hyperbolic arctangent of the real number z, @math{\arctanh(z)}.

Function: gsl_complex gsl_complex_arcsech (gsl_complex z)
This function returns the complex hyperbolic arcsecant of the complex number z, @math{\arcsech(z) = \arccosh(1/z)}.

Function: gsl_complex gsl_complex_arccsch (gsl_complex z)
This function returns the complex hyperbolic arccosecant of the complex number z, @math{\arccsch(z) = \arcsin(1/z)}.

Function: gsl_complex gsl_complex_arccoth (gsl_complex z)
This function returns the complex hyperbolic arccotangent of the complex number z, @math{\arccoth(z) = \arctanh(1/z)}.