Option Base 1
[b]Function PhTrBac2(Aa As Double, Bb As Double, Cc As Double)[/b]
ReDim MNghiem(3, 1) As Variant
Dim DelTa As Double: Dim iJ As Integer
For iJ = 1 To 3
MNghiem(iJ, 1) = ""
Next iJ
DelTa = (Bb ^ 2 - (4 * Aa * Cc))
Select Case DelTa
Case Is < 0
MNghiem(1, 1) = "Phương trình vô nghiệm"
MNghiem(2, 1) = "DelTa bé hơn 0 !"
Case 0
MNghiem(1, 1) = "Phương trình có nghiệm duy nhất"
MNghiem(2, 1) = -Bb / (2 * Aa)
Case Is > 0
MNghiem(3, 1) = (-Bb + DelTa ^ (1 / 2)) / (2 * Aa)
MNghiem(2, 1) = (-Bb - DelTa ^ (1 / 2)) / (2 * Aa)
MNghiem(1, 1) = "Phương trình có hai nghiệm "
End Select
PhTrBac2 = MNghiem()
[b]End Function[/b]