vb.net如何解方程 vb怎么解方程( 三 )

Else'r0
sita = pi / 3
x2r = -rr * Cos(sita) - b / 3
x2i = -ri * Sin(sita)
End If
x3r = x2r
x3i = -x2i
End If
End If
End Function
Private Function Cur(v As Double) As Double
If v0 Then
Cur = -(-v) ^ (1 / 3)
Else
Cur = v ^ (1 / 3)
End If
End Function
Private Function Argument(a As Double, b As Double) As Double
Dim sita As Double, pi As Double
'pi = 3.14159265358979
pi = 4 * Atn(1)
If a = 0 Then
If b = 0 Then
Argument = pi / 2
Else
Argument = -pi / 2
End If
Else
sita = Atn(Abs(b / a))
If a0 Then
If b = 0 Then
Argument = sita
Else
Argument = -sita
End If
ElseIf a0 Then
If b = 0 Then
Argument = pi - sita
Else
Argument = pi + sita
End If
End If
End If
End Function
二元一次方程：
Dim a, b, c As Integer
Dim x, y As Single
Dim d As Double
a = Val(InputBox("输入二次项系数"))
b = Val(InputBox("输入一次项系数"))
c = Val(InputBox("输入常数项"))
d = b ^ 2 - 4 * a * c
If d0 Then
MsgBox "方程无解"
ElseIf d = 0 Then
x = -b / (2 * a)
MsgBox "方程有一个解："x
Else
x = (-b + Sqr(d)) / (2 * a)
y = (-b - Sqr(d)) / (2 * a)
MsgBox "方程有两个解："x"和"y
End If
三元一次方程：
方程组如下,
ax+by+cz=d
a'x+b'y+c'z=d'
a"x+b"y+c"z=d"
其中x,y,z为未知数,a,a',a",b,b',b",c,c',c",d,d',d",为用户输入的数值
解N元一次方程， indat为N+1行、N列的数组，outdat为N个元素的数组
Public Sub 解方程(ByRef InDat() As Double, ByVal InDatCount As Long, ByRef OutDat() As Double, ByRef OutDatCount As Long)
Dim Xt() As Double
Dim Dt As Double
Dim Ss As Long
Dim OtSCount As Long
Dim XtOut() As Double
If InDatCount1 Then
ReDim Xt(1 To InDatCount - 1, 1 To InDatCount) As Double
For j = 1 To InDatCount - 1 '行
For i = 2 To InDatCount + 1 '列
Xt(j, i - 1) = InDat(j, i) * InDat(InDatCount, 1) / InDat(1, 1) - InDat(InDatCount, i)
Next i
Next j
OtSCount = 0
解方程 Xt, InDatCount - 1, XtOut, OtSCount
Dt = 0
For i = 1 To InDatCount - 1
Dt = Dt + InDat(InDatCount, i + 1) * XtOut(i)
Next i
Dt = Dt + InDat(InDatCount, i + 1)
ReDim Preserve OutDat(1 To 1 + OtSCount) As Double
OutDat(1) = -Dt / InDat(InDatCount, 1)
For i = 2 To OtSCount + 1
OutDat(i) = XtOut(i - 1)
Next i
OutDatCount = 1 + OtSCount
Else
ReDim OutDat(1 To 1) As Double
If InDat(1, 1)0 Then
OutDat(1) = -InDat(1, 2) / InDat(1, 1)
Else
OutDat(1) = 0
End If
OutDatCount = 1
End If
End Sub
如何用VB求一元二次方程的虚数解（一定是虚数解）。vb代码如下：
Private Sub Command1_Click()
Dim a As Single, b As Single, c As Single
Dim d As Single, x1 As Single, x2 As Single
a = InputBox("请输入一元二次方程的系数a")
b = InputBox("请输入一元二次方程的系数b")
c = InputBox("请输入一元二次方程的系数c")
If a = 0 Then
a = InputBox("因为a≠0，你输入的a＝0，请重新输入系数a")
End If
d = b * b - 4 * a * c
If d = 0 Then
x1 = (-b + Sqr(d)) / (2 * a)
x2 = (-b - Sqr(d)) / (2 * a)
Print "系数为"; a; b; c; "的一元二次方程的根分别为"; x1
Print "系数为"; a; b; c; "的一元二次方程的根分别为"; x2
Else
Print "此方程在实数范围内无解"
End If
End Sub
一、按钮“求一元二次方程”的vb代码如下：
Private Sub Command1_Click()
a = Text1.Text
b = Text2.Text