# ASIN

The ASIN function returns the arcsine of a given numeric expression as an angle, expressed in radians.

## Syntax

`ASIN(number)`

### Parameters

#### number

This is a numeric value ranging between -1 and 1. If the parameter is `null`, the function will also return `null`.

## Examples

In this example, the ASIN function calculates the arcsine of 0.9:

```esql
ROW a=.9
| EVAL asin=ASIN(a)
```

In this example, the ASIN function calculates the arcsine of -0.5:

```esql
ROW a = -.5
| EVAL asin = ASIN(a)
```
