---
title: math.acosh() function
description: math.acosh() returns the inverse hyperbolic cosine of x.
url: https://docs.influxdata.com/flux/v0/stdlib/math/acosh/
estimated_tokens: 1381
product: Flux
version: v0
---

# math.acosh() function

-   Flux 0.22.0+
-   View InfluxDB support

`math.acosh()` returns the inverse hyperbolic cosine of `x`.

##### Function type signature

```js
(x: float) => float
```

For more information, see [Function type signatures](/flux/v0/function-type-signatures/).

## Parameters

### x

(Required) Value to operate on.

`x` should be greater than 1. If less than 1 the operation will return `NaN`.

## Examples

-   [Return the inverse hyperbolic cosine of a value](#return-the-inverse-hyperbolic-cosine-of-a-value)
-   [Use math.acosh in map](#use-mathacosh-in-map)

### Return the inverse hyperbolic cosine of a value

```js
import "math"

math.acosh(x: 1.22)
```

### Use math.acosh in map

```js
import "math"

data
    |> map(fn: (r) => ({r with _value: math.acosh(x: r._value)}))
```

[](#view-example-input-and-output)

View example input and output

#### Input data

| _time | *tag | _value |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | t1 | -0.21800000000000003 |
| 2021-01-01T00:00:10Z | t1 | 1.092 |
| 2021-01-01T00:00:20Z | t1 | 0.735 |
| 2021-01-01T00:00:30Z | t1 | 1.7530000000000001 |
| 2021-01-01T00:00:40Z | t1 | 1.5230000000000001 |
| 2021-01-01T00:00:50Z | t1 | 0.443 |

| _time | *tag | _value |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | t2 | 1.9850000000000003 |
| 2021-01-01T00:00:10Z | t2 | 0.497 |
| 2021-01-01T00:00:20Z | t2 | -0.375 |
| 2021-01-01T00:00:30Z | t2 | 1.977 |
| 2021-01-01T00:00:40Z | t2 | 1.3860000000000001 |
| 2021-01-01T00:00:50Z | t2 | 0.18600000000000003 |

#### Output data

| _time | _value | *tag |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | NaN | t1 |
| 2021-01-01T00:00:10Z | 0.42572984537574377 | t1 |
| 2021-01-01T00:00:20Z | NaN | t1 |
| 2021-01-01T00:00:30Z | 1.1608966388962805 | t1 |
| 2021-01-01T00:00:40Z | 0.9827177940622978 | t1 |
| 2021-01-01T00:00:50Z | NaN | t1 |

| _time | _value | *tag |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | 1.308254013849232 | t2 |
| 2021-01-01T00:00:10Z | NaN | t2 |
| 2021-01-01T00:00:20Z | NaN | t2 |
| 2021-01-01T00:00:30Z | 1.3035758471451702 | t2 |
| 2021-01-01T00:00:40Z | 0.8525776257667146 | t2 |
| 2021-01-01T00:00:50Z | NaN | t2 |