Private Sub CubicRootSample()
    ' Print some samples of the CubicRoot function.

    Debug.Print "AX^3 + BX^2 + CX + D = 0"
    
    Randomize

    Dim intCurTry As Integer
    For intCurTry = 1 To 4
        Debug.Print

        Dim A As Double
        Dim B As Double
        Dim C As Double
        Dim D As Double
        A = Rnd - 0.5
        B = Rnd - 0.5
        C = Rnd - 0.5
        D = Rnd - 0.5
    
        Debug.Print "A = " & A
        Debug.Print "B = " & B
        Debug.Print "C = " & C
        Debug.Print "D = " & D

        Dim X1 As Variant
        Dim X2 As Variant
        Dim X3 As Variant
        X1 = CubicRoot(A, B, C, D, 1)
        X2 = CubicRoot(A, B, C, D, 2)
        X3 = CubicRoot(A, B, C, D, 3)
    
        Debug.Print "X1 = " & X1
        Debug.Print "X2 = " & X2
        Debug.Print "X3 = " & X3

        ' Evaluate the cubic expression for both roots.
        If Not IsNull(X1) Then Debug.Print "Eval X1 = " & CubicExpr(A, B, C, D, X1)
        If Not IsNull(X2) Then Debug.Print "Eval X2 = " & CubicExpr(A, B, C, D, X2)
        If Not IsNull(X3) Then Debug.Print "Eval X3 = " & CubicExpr(A, B, C, D, X3)
    Next intCurTry
End Sub