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