CATANH(3) BSD Library Functions Manual CATANH(3)

NAME
     ccaattaannhh - complex inverse hyperbolic tangent function

SYNOPSIS
     double complex
     ccaattaannhh(double complex z);

     long double complex
     ccaattaannhhll(long double complex z);

     float complex
     ccaattaannhhff(float complex z);

DESCRIPTION
     ccaattaannhh(z) computes the inverse hyperbolic tangent of the complex float-
     ing-point number z, with branch cuts outside the interval [-1, 1] along
     the real axis.

     ccaattaannhh() returns values in a strip of the complex plane with imaginary
     part in the interval [-Pi/2, Pi/2].

     For all complex floating point numbers z,

           catanh(conj(z)) = conj(catanh(z)).
           catanh(-z) = -catanh(z)

SSPPEECCIIAALL VVAALLUUEESS
     The symmetries of catanh() are used to abbreviate the specification of
     special values.

     ccaattaannhh(0 + 0i) returns 0 + 0 i.

     ccaattaannhh(0 + NaN i) returns 0 + NaN i.

     ccaattaannhh(1 + 0i) returns inf + 0i and raises the divide-by-zero flag.

     ccaattaannhh(x + inf i) returns 0 + Pi/2 i, for finite positive-signed x.

     ccaattaannhh(x + NaN i) returns NaN + NaN i, for non-zero finite x.

     ccaattaannhh(inf + yi) returns 0 + Pi/2 i, for finite positive-signed y.

     ccaattaannhh(inf + inf i) returns 0 + Pi/2 i.

     ccaattaannhh(inf + NaN i) returns 0 + NaN i.

     ccaattaannhh(NaN + yi) returns NaN + NaN i, for finite y.

     ccaattaannhh(NaN + inf i) returns 0 + Pi/2 i.

     ccaattaannhh(NaN + NaN i) returns NaN + NaN i.

NNOOTTEESS
SEE ALSO
     ctanh(3) complex(3)

STANDARDS     The ccaattaannhh() function conforms to ISO/IEC 9899:1999(E).

4th Berkeley Distribution      November 9, 2006      4th Berkeley Distribution