---
title: math.tan() function
description: >
  `math.tan()` returns the tangent of the radian argument `x`.
menu:
  flux_v0_ref:
    name: math.tan
    parent: math
    identifier: math/tan
weight: 101
---

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`math.tan()` returns the tangent of the radian argument `x`.



##### Function type signature

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

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

## Parameters

### x
({{< req >}})
Value to operate on.




## Examples

- [Return the tangent of a radian value](#return-the-tangent-of-a-radian-value)
- [Use math.tan in map](#use-mathtan-in-map)

### Return the tangent of a radian value

```js
import "math"

math.tan(x: 3.14)// -0.001592654936407223


```


### Use math.tan in map

```js
import "math"
import "sampledata"

sampledata.float()
    |> map(fn: (r) => ({r with _value: math.tan(x: r._value)}))

```

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{{% expand "View example input and output" %}}

#### Input data

| _time                | *tag | _value  |
| -------------------- | ---- | ------- |
| 2021-01-01T00:00:00Z | t1   | -2.18   |
| 2021-01-01T00:00:10Z | t1   | 10.92   |
| 2021-01-01T00:00:20Z | t1   | 7.35    |
| 2021-01-01T00:00:30Z | t1   | 17.53   |
| 2021-01-01T00:00:40Z | t1   | 15.23   |
| 2021-01-01T00:00:50Z | t1   | 4.43    |

| _time                | *tag | _value  |
| -------------------- | ---- | ------- |
| 2021-01-01T00:00:00Z | t2   | 19.85   |
| 2021-01-01T00:00:10Z | t2   | 4.97    |
| 2021-01-01T00:00:20Z | t2   | -3.75   |
| 2021-01-01T00:00:30Z | t2   | 19.77   |
| 2021-01-01T00:00:40Z | t2   | 13.86   |
| 2021-01-01T00:00:50Z | t2   | 1.86    |


#### Output data

| _time                | _value              | *tag |
| -------------------- | ------------------- | ---- |
| 2021-01-01T00:00:00Z | 1.4332105287001917  | t1   |
| 2021-01-01T00:00:10Z | 13.206812562189944  | t1   |
| 2021-01-01T00:00:20Z | 1.8132901361470621  | t1   |
| 2021-01-01T00:00:30Z | -3.8961501504145963 | t1   |
| 2021-01-01T00:00:40Z | -0.5180248236402568 | t1   |
| 2021-01-01T00:00:50Z | 3.446580763443108   | t1   |

| _time                | _value              | *tag |
| -------------------- | ------------------- | ---- |
| 2021-01-01T00:00:00Z | 1.5589299766884657  | t2   |
| 2021-01-01T00:00:10Z | -3.7955688539089367 | t2   |
| 2021-01-01T00:00:20Z | -0.6965508511114601 | t2   |
| 2021-01-01T00:00:30Z | 1.3144743689586664  | t2   |
| 2021-01-01T00:00:40Z | 3.515068256260714   | t2   |
| 2021-01-01T00:00:50Z | -3.3608276755646553 | t2   |

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