# ACos()

Returns the angle whose cosine is the value passed as the argument.

```
ACos( number=number );
```

**Returns:** number

# Arguments

| Argument | Type | Required | Description | Default |
|----------|------|----------|-------------|---------|
| number | number | Yes | The value to be converted into an angle. Must be between -1 and 1. |  |

# Examples

The following code example will output an example number returned from the acos() function.

```cfml
<cfset inputValue = 0.5>
<cfoutput>#aCos(inputValue)#</cfoutput>
```







# Categories

[Numbers](../../categories/number.md), [Math](../../categories/math.md)

# See Also

[numeric.aCos()](../objects/numeric/acos.md)