---
title: math.asin() function
description: math.asin() returns the arcsine of x in radians.
url: https://docs.influxdata.com/flux/v0/stdlib/math/asin/
estimated_tokens: 1381
product: Flux
version: v0
---

# math.asin() function

-   Flux 0.22.0+
-   View InfluxDB support

`math.asin()` returns the arcsine of `x` in radians.

##### 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 and less than 1. Otherwise the function will return `NaN`.

## Examples

-   [Return the arcsine of a value](#return-the-arcsine-of-a-value)
-   [Use math.asin in map](#use-mathasin-in-map)

### Return the arcsine of a value

```js
import "math"

math.asin(x: 0.22)
```

### Use math.asin in map

```js
import "math"

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

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

View example input and output

#### Input data

| _time | *tag | _value |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | t1 | -0.021800000000000003 |
| 2021-01-01T00:00:10Z | t1 | 0.1092 |
| 2021-01-01T00:00:20Z | t1 | 0.0735 |
| 2021-01-01T00:00:30Z | t1 | 0.1753 |
| 2021-01-01T00:00:40Z | t1 | 0.15230000000000002 |
| 2021-01-01T00:00:50Z | t1 | 0.0443 |

| _time | *tag | _value |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | t2 | 0.1985 |
| 2021-01-01T00:00:10Z | t2 | 0.0497 |
| 2021-01-01T00:00:20Z | t2 | -0.0375 |
| 2021-01-01T00:00:30Z | t2 | 0.1977 |
| 2021-01-01T00:00:40Z | t2 | 0.1386 |
| 2021-01-01T00:00:50Z | t2 | 0.018600000000000002 |

#### Output data

| _time | _value | *tag |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | -0.021801727074707577 | t1 |
| 2021-01-01T00:00:10Z | 0.10941820137571553 | t1 |
| 2021-01-01T00:00:20Z | 0.07356633896021608 | t1 |
| 2021-01-01T00:00:30Z | 0.17621047844966892 | t1 |
| 2021-01-01T00:00:40Z | 0.1528950055407725 | t1 |
| 2021-01-01T00:00:50Z | 0.044314502528968014 | t1 |

| _time | _value | *tag |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | 0.1998272282367503 | t2 |
| 2021-01-01T00:00:10Z | 0.04972048335509017 | t2 |
| 2021-01-01T00:00:20Z | -0.03750879462898862 | t2 |
| 2021-01-01T00:00:30Z | 0.19901105310181802 | t2 |
| 2021-01-01T00:00:40Z | 0.13904763050983682 | t2 |
| 2021-01-01T00:00:50Z | 0.0186010726429996 | t2 |