# C Programming/complex.h/casinh

< C Programming | complex.h(Redirected from C Programming/C Reference/complex.h/casinh)## Contents

## PrototypesEdit

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

## DescriptionEdit

`casinh`

is one of the Standard C library functions in the complex.h header file. It is used to calculate the complex and inverse hyperbolic sine of given angle or number. Just like sine operator has inverse as sin inverse, hyperbolic sine of complex number has this as an inverse function.

if casinh(x) = y, then x = csinh(y). It can be also evaluated as: casinh(x) = clog(x+csqrt(x*x+1))

### return valueEdit

This function returns complex arc hyperbolic sine,in the range mathematically unbounded along real axis and in the interval along imaginary axis.

### compatibilityEdit

Win32, C99 7.3.6.2