casinh(), casinhf(), casinhl()

Updated: October 26, 2022

Compute the complex inverse hyperbolic sine


#include <complex.h>

double complex casinh( double complex z );

float complex casinhf( float complex z );

long double complex casinhl( long double complex z );


The value that you want to get the complex inverse hyperbolic sine of.


The general-purpose math library.
(QNX Neutrino 7.1 or later) A library that optimizes the code for ARMv8.2 chips that have Scalable Vector Extension hardware.

Your system requirements will determine how you should work with these libraries:

Note: Compile your program with the -fno-builtin option to prevent the compiler from using a built-in version of the function.


These functions compute the complex inverse hyperbolic sine of z, with branch cuts outside the interval [−i; +i] along the imaginary axis.

To check for error situations, use feclearexcept() and fetestexcept(). For example:


The complex inverse hyperbolic sine of z.

If z is: These functions return: Errors:
0 + 0i 0 + 0i
x + Infi (for any positive finite x) Inf + (π/2)i
x + NaNi (for any finite x) NaN + NaNi
Inf + yi (for any positive finite y) Inf + 0i
Inf + Infi Inf + (π/4)i
Inf + NaNi Inf + NaNi
NaN + 0i NaN + 0i
NaN + yi (for any finite nonzero y) NaN + NaNi
NaN + Infi ±Inf ± NaNi, where the sign of the real part is unspecified
NaN + NaNi NaN + NaNi

These functions raise FE_INEXACT if the FPU reports that the result can't be exactly represented as a floating-point number.


C11, POSIX 1003.1

Cancellation point No
Interrupt handler Yes
Signal handler Yes
Thread Yes