---
title: "asin"
description: "Returns the arc sine of number"
---

# asin

> Returns the arc sine of number

This function is used by Ignition's Expression language.
## Description
Returns the arc sine of a number, which must be a number between -1 and 1. The results will be an angle expressed in radians in the range of -pi/2 through pi/2.

## Syntax
`asin(number)`

### Parameters

| Type | Parameter | Description |
|---|---|---|
| Float | `number` | The number to get the arc sine of. Must be a value between -1 and 1. |

### Results
**Float** - The arc sine of the value provided.

## Examples
```python title="Code Snippet"
asin(.38) //returns 0.3898
```