> For the complete documentation index, see [llms.txt](https://doc.sysdevmobile.com/kalipso5/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.sysdevmobile.com/kalipso5/developing/form/expressions/functions/functions-descriptions/numeric-functions/arc-tangent.md).

# Arc Tangent

This Function returns a *\<numeric>* expressed in radians, which is the Arc Tangent of the specified **Value**.

Function available for the following operating systems:

![](/files/-MAlQBZuuTnc6hyzKSVQ)

### Parameters

* **Value** *\<numeric> -* Value to retrieve the Arc Tangent from.

### **Examples**

* *Example 1*

ATan(1)\
**Result** = 45