Public Function Asn(x As Double) As Double
  If x = 1 Then
    Asn = GetPi / 2
  ElseIf x = -1 Then
    Asn = -GetPi / 2
  ElseIf x <= 1 Then
    Asn = Atn(x / Sqr((-x * x) + 1))
  End If
End Function

- "Computers are like air conditioners. They stop working properly when you open Windows"