[Overview][Constants][Types][Classes][Procedures and functions][Variables][Index] | Reference for unit 'System' (#rtl)

# ArcTan

Calculate inverse tangent

## Declaration

Source position: mathh.inc line 109

`function ArcTan(`
`d: ValReal`
`):ValReal;`

## Description

Arctan returns the Arctangent of X, which can be any Real type. The resulting angle is in radial units.

## Errors

None

## See also

Sin |  | Calculate sine of angle
Cos |  | Calculate cosine of angle

## Example

    Program Example4;

    { Program to demonstrate the ArcTan function. }

    Var R : Real;

    begin
      R:=ArcTan(0);      { R:=0 }
      R:=ArcTan(1)/pi;   { R:=0.25 }
    end.

Documentation generated on: May 14 2021