一元二次方程的虚根怎么求

界面：代码：Private Sub Command1_Click() Dim a As Single, b As Single, c As Single, d As Single Label8.Caption = "" Label9.Caption = "" a = Val(Text1.Text): b = Val(Text2.Text): c = Val(Text3.Text) d = b ^ 2 - 4 * a * c If d = 0 Then Label8.Caption = "x1=x2=" & -b / (2 * a) ElseIf d > 0 Then Label8.Caption = "x1=" & (-b - Sqr(b ^ 2 - 4 * a * c)) / (2 * a) Label9.Caption = "x2=" & (-b + Sqr(b ^ 2 - 4 * a * c)) / (2 * a) Else Label8.Caption = "x1=" & -b / (2 * a) & "-" & Sqr(4 * a * c - b ^ 2) / (2 * a) & "i" Label9.Caption = "x2=" & -b / (2 * a) & "+" & Sqr(4 * a * c - b ^ 2) / (2 * a) & "i" End IfEnd Sub运行效果本回答被网友采纳