# Math.acosh

## Function

Inverse hyperbolic cosine. Returns the inverse hyperbolic cosine of value.

## Syntax

```bt
Math.acosh(value)
```

## Parameters

| Parameters | Type | Required | Default value | Description |
| ------ | ------ | ------ | ------ | ------ |
| value | Number | Yes | None | The number involved in the calculation. |

## Return value

| Type | Description |
| ------ | ------ |
| Int/Float | Returns the inverse hyperbolic cosine of value. An Int is returned for integer results, and a Float for non-integer or non-finite results. |

## Example

```bt
result = Math.acosh(1)

// Output: 0
print result
```

## Notes

- When value is less than 1, NaN is returned according to f64 rules.