# Function Reference

# Tan

Calculates the tangent of a number.

Tan ( expression )

## Parameters

expression | Value in radians.

## Return Value

Returns the trigonometric tangent of the number.

## Remarks

1° = pi / 180 radians.
Note that Tan() is "infinite" for ... -3PI/2, -PI/2, PI/2, 3PI/2, 5PI/2, ... and tends to return 1.63317787283838e+016 for such multiples of Pi-halves.

## Related

ACos, ASin, ATan, Cos, Sin

## Example

    #include <MsgBoxConstants.au3>

    Example()

    Func Example()
        ; Assign a Local constant variable the approximate PI number.
        Local Const $PI = 3.141592653589793

        ; Assign a Local variable the tangent of PI / 4.
        Local $fTan1 = Tan($PI / 4)

        ; Display the result.
        MsgBox($MB_SYSTEMMODAL, "", $fTan1)

        ; Assign a Local variable the formula to switch from radian to degree (equals to one degree in radian).
        Local $iDegToRad = $PI / 180

        ; Assign a Local variable the tangent of 90 degrees (firstly converted to radians).
        Local $fTan2 = Tan(90 * $iDegToRad)

        ; Display the result.
        MsgBox($MB_SYSTEMMODAL, "", $fTan2)
    EndFunc   ;==>Example