# ATN

## Syntax

```
ATN(numericExpression)
```

## Description

Returns the arc tangent value of the given argument. Argument must be a numeric expression. Returned value type is float.

## Examples

```
REM Arc tangent value
PRINT "Arc Tangent value of a is "; ATN(a)
```

## Remarks

- This function is 100% Sinclair BASIC Compatible
- If the given argument type is not float, it will be converted to float before operating with it.