[discrete]
[[esql-acos]]
=== `ACOS`

*Syntax*

[.text-center]
image::esql/functions/signature/acos.svg[Embedded,opts=inline]

*Parameters*

`n`::
Numeric expression. If `null`, the function returns `null`.

*Description*

Returns the {wikipedia}/Inverse_trigonometric_functions[arccosine] of `n` as an
angle, expressed in radians.

*Supported types*

include::types/acos.asciidoc[]

*Example*

[source.merge.styled,esql]
----
include::{esql-specs}/floats.csv-spec[tag=acos]
----
[%header.monospaced.styled,format=dsv,separator=|]
|===
include::{esql-specs}/floats.csv-spec[tag=acos-result]
|===