Attribute VB_Name = "Module1"

Sub DERIVS(X, Y(), DYDX())
      Dim Y1(4)
      DYDX(1) = -Y1(2)
      DYDX(2) = Y1(1) - (1# / X) * Y1(2)
      DYDX(3) = Y1(2) - (2# / X) * Y1(3)
      DYDX(4) = Y1(3) - (3# / X) * Y1(4)
End Sub