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# Math.atanh()

The **`Math.atanh()`** function returns the inverse hyperbolic tangent of a number. 

## Syntax

```js
Math.atanh(x)
```

### Parameters

- `x`
  - : A number between -1 and 1, inclusive.

### Return value

The inverse hyperbolic tangent of `x`. If `x` is 1, returns `Infinity`. If `x` is -1, returns `-Infinity`. If `x` is less than -1 or greater than 1, returns `NaN`.

## Description

Because `atanh()` is a static method of `Math`, you always use it as `Math.atanh()`, rather than as a method of a `Math` object you created (`Math` is not a constructor).

