Tan function
Tan( angle )
Returns the tangent of an angle as a double.
The parameter angle must be a valid angle expressed in radians.
Example
' This sample program show the use of the Tan function 
 
Sub Main()
   Dim Msg, Pi   ' Declare variables.
   Pi = 4 * Atn(1)   ' Calculate Pi.
   Msg = "Pi is equal to " & Pi
   MsgBox Msg   ' Display results.
   x = Tan(Pi/4)
   MsgBox  x & " is the tangent of Pi/4"
End Sub