[cfp-interest 3593] Re: csinh

[Damian McGuckin]

On Fri, 12 Sep 2025, Fred J. Tydeman wrote:

> C23: G.6.3.5 The csinh functions has these two requirements:
>
> - csinh(+0 + iNaN) returns ?0 + iNaN (where the sign of the real part of the result is unspeci-
> fied).
>
> - csinh(NaN + i0) returns NaN + i0.
>
> Since csinh( x + I*y ) == sinh(x)*cos(y) + I*cosh(x)*sin(y)
>
> It seems to me that the last case should be:

> - csinh(NaN + i0) returns NaN +/- i0 (where the sign of the imaginary
>   part of the result is unspecified).

Sounds good to me - Damian

P.S. Are there other similar expressions elsewhere?