#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 cosine of PI / 4 (equals to Sqrt(2) / 2).
        Local $fCos1 = Cos($PI / 4)

        ; Display the result.
        MsgBox($MB_SYSTEMMODAL, "", $fCos1)

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

        ; Assign a Local variable the cosine of 90 degrees (firstly converted to radians).
        Local $fCos2 = Cos(90 * $fDegToRad)

        ; Display the result.
        MsgBox($MB_SYSTEMMODAL, "", $fCos2)
EndFunc   ;==>Example