# `Acos`

``Acos( value )``
``Acos( value )``
``Acos( value )``
``Acos( value )``
``acos( value )``
``Acos( value )``
``Acos( value )``

## Description

The `Acos` function is a trigonometric function which calculates ratios of the lengths of the sides of right triangles. `Acos` returns the arc cosine of a number.

## Parameters

Argument Type Definition and Requirements

`value`

The Number whose arc cosine should be returned.

## Returns

A Number which is the arc cosine of `value`.

## Examples

The following query returns the arc cosine of 0.5:

``````try
{
Value result = await client.Query(
Acos(0.5)
);

Console.WriteLine(result);
}
catch (Exception e)
{
Console.WriteLine(\$"ERROR: {e.Message}");
}``````
``DoubleV(1.0471975511965979)``
``````result, err := client.Query(
f.Acos(0.5))

if err != nil {
fmt.Fprintln(os.Stderr, err)
} else {
fmt.Println(result)
}``````
``1.0471975511965979``
``````System.out.println(
client.query(
Acos(Value(0.5))
).get());``````
``1.0471975511965979``
``````client.query(
q.Acos(0.5)
)
.then((ret) => console.log(ret))
.catch((err) => console.error('Error: %s', err))``````
``1.0471975511965979``
``````result = client.query(
q.acos(0.5)
)
print(result)``````
``1.0471975511965979``
``````try {
println(Await.result(
client.query(
Acos(0.5)
),
5.seconds
))} catch {
case unknown: Throwable => println("Error: " + unknown.getMessage())
}``````
``1.0471975511965979``
``Acos(0.5)``
``1.0471975511965979``