# Futurebasic/Language/Reference/atanh

## Atanh

edit### Function

edit✔ Appearance ✔ Standard ✔ Console

### Syntax

editresult# = atanh( expr )

### Description

editReturns the inverse hyperbolic tangent of

. This is the inverse of the *expr*`tanh`

function, so that `atanh`

`(tanh(`

equals *x*))

. *x*`atanh`

always returns a double-precision result.

### Notes

editNo special notes.