- `Y = acosh (X)`

Compute the inverse hyperbolic cosine for each element of `X`.

This is defined as

> > `%acosh(z) = ln(sqrt(-1+z^2)+z)%`

See also: `cosh`.

### References

- https://www.mathworks.com/help/matlab/ref/acosh.html
- https://octave.sourceforge.io/octave/function/acosh.html
- https://mathworld.wolfram.com/InverseHyperbolicFunctions.html
- https://en.wikipedia.org/wiki/Inverse_hyperbolic_functions