NAME

casinh, casinhf, casinhl — complex arc hyperbolic sine functions

SYNOPSIS

#include <complex.h>

double complex casinh(double complex z);
float complex casinhf(float complex z);
long double complex casinhl(long double complex z);


DESCRIPTION

^[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2024 defers to the ISO C standard.

These functions shall compute the complex arc hyperbolic sine of z, with branch cuts outside the interval [-i, +i] along the imaginary axis.

RETURN VALUE

These functions shall return the complex arc hyperbolic sine value, in the range of a strip mathematically unbounded along the real axis and in the interval [-iℼ/2, +iℼ/2] along the imaginary axis.

^[MXC] casinh(conj(z)), casinhf(conjf(z)), and casinhl(conjl(z)) shall return exactly the same value as conj(casinh(z)), conjf(casinhf(z)), and conjl(casinhl(z)), respectively, and casinh(-z), casinhf(-z), and casinhl(-z) shall return exactly the same value as -casinh(z), -casinhf(z), and -casinhl(z), respectively, including for the special values of z below.

If z is +0 + i0, 0 + i0 shall be returned.

If z is x + iInf where x is positive-signed and finite, +Inf + iℼ/2 shall be returned.

If z is x + iNaN where x is finite, NaN + iNaN shall be returned and the invalid floating-point exception may be raised.

If z is +Inf + iy where y is positive-signed and finite, +Inf + i0 shall be returned.

If z is +Inf + iInf, +Inf + iℼ/4 shall be returned.

If z is +Inf + iNaN, +Inf + iNaN shall be returned.

If z is NaN + i0, NaN + i0 shall be returned.

If z is NaN + iy where y is non-zero and finite, NaN + iNaN shall be returned and the invalid floating-point exception may be raised.

If z is NaN + iInf, ±Inf + iNaN shall be returned; the sign of the real part of the result is unspecified.

If z is NaN + iNaN, NaN + iNaN shall be returned.

ERRORS

No errors are defined.

EXAMPLES

None.

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

csinh

XBD <complex.h>

CHANGE HISTORY

First released in Issue 6. Derived from the ISO/IEC 9899:1999 standard.

Issue 8

Austin Group Defect 1302 is applied, aligning these functions with the ISO/IEC 9899:2018 standard.