# ACOS

Returns the arc cosine of **x** in radians, or NULL if **x** is not in the range \[-1, 1].

## Syntax

```sql

ACOS (x)

```

## Arguments

* x: the argument

## Return Type

Float or double. NULL if **x** is NULL or invalid.

## Examples

```sql
SELECT ACOS(1);

```

```output

+---------+
| ACOS(1) |
+---------+
|       0 |
+---------+

```

***

Modified at: February 24, 2023

Source: [/db/v9.1/reference/sql-reference/numeric-functions/acos/](https://docs.singlestore.com/db/v9.1/reference/sql-reference/numeric-functions/acos/)

(An index of the documentation is available at /llms.txt)