## TAN

The `TAN` function in ES|QL is used to calculate the Tangent of an angle. The angle should be provided in radians.

### Syntax

The syntax for using the `TAN` function is as follows:

`TAN(angle)`

Here, `angle` is the angle in radians for which you want to calculate the Tangent. If `angle` is null, the function will return null.

### Examples

Here are a couple of examples showing how to use the `TAN` function in ES|QL:

```esql
ROW a=1.8
| EVAL tan = TAN(a)
```

In this example, the `TAN` function is used to calculate the Tangent of the angle `1.8` radians.

```esql
ROW a=3.14
| EVAL tan = TAN(a)
```

In this example, the `TAN` function is used to calculate the Tangent of the angle `3.14` radians.