> ## Documentation Index
> Fetch the complete documentation index at: https://www.integrate.io/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# ETL: ACOS

> Compute the arc cosine (inverse cosine) of a numeric value in radians. Use for trigonometric calculations in ETL data transformations.

## Description

Returns the arc cosine of a number.

## Syntax

`ACOS(numeric_expression)`

## Examples

`ACOS(1)` returns 0.0

## Return value datatype

Double

## Impact of null value

If input is null, returns null.