一元二次方程求解公式

来源：百度知道 编辑：UC知道 时间：2024/07/03 15:33:10
Private Sub Form_Click()
Dim x As Long, a As Long, b As Long, c As Long, p As Single, q As Single, z As Single
a = Val(Text1.Text)
b = Val(Text2.Text)
c = Val(Text3.Text)
y = a * x ^ 2 + b * x + c = 0
If b ^ 2 - 4 * a * c >= 0 Then
z = Sqr(b ^ 2 - 4 * a * c)
p = (-b + z) / (2 * a)
q = (-b - z) / (2 * a)
Text4.Text = Str(p)
Text5.Text = Str(q)
Else
MsgBox ("available!!!")
End If
End Sub
---------------大家看看还有什么要改进的地方没?------------------------------------------------------------------------------------

a,b,c的数据类型应该是Single
dim a!,b!,c!,d!
a = Val(Text1.Text)
b = Val(Text2.Text)
c = Val(Text3.Text)
d = b ^ 2 - 4 * a * c
If d >= 0 Then
d=sqr(d)
Text4.Text = (-b + d) / 2 / a
Text5.Text = (-b - d) / 2 / a
Else
MsgBox ("available!!!")
End If

y = a * x ^ 2 + b * x + c = 0 这一行去掉。其它没问题。

运算是没有什么问题，但是，如楼上，y = a * x ^ 2 + b * x + c = 0一点用也没有！