VB解一元二次方程配方法源碼

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1、VB解一元?二次方程配?方法 我也是一個?vb的超級?菜鳥，但是我運用?我所學(xué)的數(shù)?學(xué)知識，編輯了一個?解一元二次?方程的配方?法過程的這?么一個程序?。我是自己原?創(chuàng)，至于是不是?首創(chuàng)就不知?道了。(很多網(wǎng)上直?接出答案的?都是運用公?式法計算的?，那么我就想?寫個有過程?的程序，完爆數(shù)學(xué)老?師) 好了，廢話不說多?，現(xiàn)在先上測?試圖，有圖有真相?嘛。 這個程序有?幾個重點（后面源碼都?有注釋） 1、 a值要變?yōu)?正數(shù)，否則將無法?運行 2、 開不盡的數(shù)?要用根號表?示，不會像√2=1.414……這么多小數(shù)? 3、 分母有理化?，倒數(shù)第二步?的分母不能

2、?為根號（標準） 4、 移項時的符?號注意變化?。 下面是界面?介紹： 下面直接上?源碼了，有注釋自己?可以理解。 Dim a$ ,b$,c$,d$,e$,f$,g$,h$ Dim jj! Dim ii! Dim pp! Priva?te Sub Comma?nd1_C?lick() a = Text1?.Text b = Text2?.Text c = Text3?.Text d = Text4?.Text If a = 1 Then 第一步，先列出原式? Label?3.Capti?on = "x^

3、2" End If If a = -1 Then Label?3.Capti?on = "-x^2" End If If Not a = 1 And Not a = -1 Then Label?3.Capti?on = a & "x^2" End If If b > 0 Then Label?3.Capti?on = Label?3.Capti?on & "+" & b Else Label?3.Capti?on = Label?3.Capti?on & b End If If c > 0 Then Label?3.Capti?on = Label?3.Capti?

4、on & "x+" & c & "=" & d Else Label?3.Capti?on = Label?3.Capti?on & "x" & c & "=" & d End If If a < 0 Then 當a為負數(shù)?時，每個項同時?乘以-1 a = -a b = -b c = -c d = -d End If c = c - d 移項，將右邊移向?左邊 If a = 0 Then 判斷有無解? Label?3.Capti?on = Label?3.Capti?on & vbCrL?f & "原方程無解?" End If If (b ^ 2)

5、- (4 * a * c) < 0 Then Label?3.Capti?on = Label?3.Capti?on & vbCrL?f & "原方程無解?" End If If a = 1 Then 第二步，寫出移項后?的結(jié)果 Label?3.Capti?on = Label?3.Capti?on & vbCrL?f & "x^2" End If If a = -1 Then Label?3.Capti?on = Label?3.Capti?on & vbCrL?f & "-x^2" End If If Not a = 1 And Not a = -1 Then La

6、bel?3.Capti?on = Label?3.Capti?on & vbCrL?f & a & "x^2" End If If b > 0 Then Label?3.Capti?on = Label?3.Capti?on & "+" & b Else Label?3.Capti?on = Label?3.Capti?on & b End If If c > 0 Then Label?3.Capti?on = Label?3.Capti?on & "x+" & c & "=0" Else Label?3.Capti?on = Label?3.Capti?on & "x"

7、& c & "=0" End If e = (b ^ 2) / (4 * a) 算出適合配?方的新c值? f = e - c 新c值與原?c值的差，兩邊同時加?差值 If a = 1 Then 第三步，寫出初步配?方的結(jié)果 Label?3.Capti?on = Label?3.Capti?on & vbCrL?f & "x^2" End If If a = -1 Then Label?3.Capti?on = Label?3.Capti?on & vbCrL?f & "-x^2" End If If Not a = 1 And Not a = -1 Then La

8、bel?3.Capti?on = Label?3.Capti?on & vbCrL?f & a & "x^2" End If If b > 0 Then Label?3.Capti?on = Label?3.Capti?on & "+" & b Else Label?3.Capti?on = Label?3.Capti?on & b End If If e > 0 Then Label?3.Capti?on = Label?3.Capti?on & "x+" & e & "=" & f Else Label?3.Capti?on = Label?3.Capti?on & "

9、x" & e & "=" & f End If g = (-b + Sqr(b ^ 2 - 4 * a * c)) / (2 * a) 后臺使用公?式法計算 h = (-b - Sqr(b ^ 2 - 4 * a * c)) / (2 * a) If g > 0 And g < 1 Then 給0 < y < 1的數(shù)前加?個0 g = "0" & g End If If g < 0 And g > -1 Then g = -g g = "-0" & g End If If h > 0 And h < 1 Then h = "0" & h End If If h

10、< 0 And h > -1 Then h = -h h = "-0" & h End If jj = Sqr(a) If a = 1 Then 第四步，運用完全平?方公式進行?配方 Label?3.Capti?on = Label?3.Capti?on & vbCrL?f & "（x" End If If a = -1 Then Label?3.Capti?on = Label?3.Capti?on & vbCrL?f & "（-x" End If If Not a = 1 And Not a = -1 Then If Not Len(CStr(jj - Fix(

11、jj))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & vbCrL?f & "（" & Sqr(a) & "x" End If If Len(CStr(jj - Fix(jj))) > 4 Then’小數(shù)大于3?位時用根號?表示，不直接開方? Label?3.Capti?on = Label?3.Capti?on & vbCrL?f & "（√" & a & "x" End If End If ------------------第一層----------------------------- ii = Sqr(e) If b

12、 > 0 Then If Not Len(CStr(ii - Fix(ii))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "+" & Sqr(e) & "）^2=" & f End If If Len(CStr(ii - Fix(ii))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "+" & "√" & e & "）^2=" & f End If End If If b < 0 Then If Not Len(CStr(ii - Fix(ii))) > 4 Then

13、Label?3.Capti?on = Label?3.Capti?on & "-" & Sqr(e) & "）^2=" & f End If If Len(CStr(ii - Fix(ii))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "-" & "√" & e & "）^2=" & f End If End If ------------------第二層---------------------------- If a = 1 Then 第五步，兩邊同時開?根號 Label?3.Capti?on = Label?3.

14、Capti?on & vbCrL?f & "x" End If If a = -1 Then Label?3.Capti?on = Label?3.Capti?on & vbCrL?f & "-x" End If If Not a = 1 And Not a = -1 Then If Not Len(CStr(jj - Fix(jj))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & vbCrL?f & "" & Sqr(a) & "x" End If If Len(CStr(jj - Fix(jj))) > 4 Then L

15、abel?3.Capti?on = Label?3.Capti?on & vbCrL?f & "√" & a & "x" End If End If If b > 0 Then If Not Len(CStr(ii - Fix(ii))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "+" & Sqr(e) & "=" End If If Len(CStr(ii - Fix(ii))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "+" & "√" & e & "=" End

16、If End If If b < 0 Then If Not Len(CStr(ii - Fix(ii))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "-" & Sqr(e) & "=" End If If Len(CStr(ii - Fix(ii))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "-" & "√" & e & "=" End If End If pp = Sqr(f) If Not Len(CStr(pp - Fix(pp))) > 4 Then

17、Label?3.Capti?on = Label?3.Capti?on & "" & Sqr(f) End If If Len(CStr(pp - Fix(pp))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "√" & f End If Label?3.Capti?on = Label?3.Capti?on & vbCrL?f & "x=" 第六步，移項，x在左 If Len(CStr(jj - Fix(jj))) > 4 Then 分母有理化?(后補分母) Label?3.Capti?on = Label?3.Capti

18、?on & "√" & a End If If a = 1 Then If Not Len(CStr(pp - Fix(pp))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "" & Sqr(f) End If If Len(CStr(pp - Fix(pp))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "√" & f End If If b > 0 Then If Not Len(CStr(ii - Fix(ii))) > 4 Then Label?3.Capti?

19、on = Label?3.Capti?on & "-" & Sqr(e) End If If Len(CStr(ii - Fix(ii))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "-" & "√" & e End If End If If b < 0 Then If Not Len(CStr(ii - Fix(ii))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "+" & Sqr(e) End If If Len(CStr(ii - Fix(ii))) > 4 T

20、hen Label?3.Capti?on = Label?3.Capti?on & "+" & "√" & e End If End If End If ------------------------第一層--------------------------- If Not a = 1 Then If Not Len(CStr(pp - Fix(pp))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "（" & Sqr(f) End If If Len(CStr(pp - Fix(pp))) > 4 Then Label

21、?3.Capti?on = Label?3.Capti?on & "（√" & f End If If b > 0 Then If Not Len(CStr(ii - Fix(ii))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "-" & Sqr(e) & "）/" End If If Len(CStr(ii - Fix(ii))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "-" & "√" & e & "）/" End If End If If b < 0 Then

22、 If Not Len(CStr(ii - Fix(ii))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "+" & Sqr(e) & "）/" End If If Len(CStr(ii - Fix(ii))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & "+" & "√" & e & "）/" End If End If If Not Len(CStr(jj - Fix(jj))) > 4 Then Label?3.Capti?on = Label?3.Capti?on

23、& Sqr(a) End If If Len(CStr(jj - Fix(jj))) > 4 Then Label?3.Capti?on = Label?3.Capti?on & a End If End If Label?3.Capti?on = Label?3.Capti?on & vbCrL?f & "x=" & g & "或x=" & h 第七步，得解 End Sub Priva?te Sub Comma?nd2_C?lick() Text1?.Text = "" Text2?.Text = "" Text3?.Text = "" Text4?.Te

24、xt = "" Label?3.Capti?on = "解題區(qū)域" End Sub Priva?te Sub Comma?nd3_C?lick() a = Text1?.Text b = Text2?.Text c = Text3?.Text d = Text4?.Text c = c - d Label?6.Visib?le = True Label?7.Visib?le = True Label?8.Visib?le = True Label?9.Visib?le = True Line1?.Visib?le = True Line2?.Visib?le

25、 = True Label?5.Capti?on = "∵a=" & a & "，b=" & b & "，c=" & c 第一步，列出a、b、c的值（格式嚴謹） Label?5.Capti?on = Label?5.Capti?on & vbCrL?f & "∴△=b^2-4ac=" & (b ^ 2) - (4 * a * c) 第二步，算出變量b?^2-4ac的值? If (b ^ 2) - (4 * a * c) < 0 Then 第三步，判斷方程有?無解 Label?5.Capti?on = Label?5.Capti?on & vbCrL?f & "∴b^2-4ac

26、< 0，方程無解。" Else If b > 0 Then Label?7.Capti?on = "-" & b & "√" & (b ^ 2) - (4 * a * c) 第四步，寫分子 Else Label?7.Capti?on = -b & "√" & (b ^ 2) - (4 * a * c) End If End If Label?8.Capti?on = 2 * a 第四步，寫分母 g = (-b + Sqr(b ^ 2 - 4 * a * c)) / (2 * a) 公式法運算? h = (-b - Sqr(b ^ 2 - 4 * a * c)) / (2

27、 * a) If g > 0 And g < 1 Then 加0 g = "0" & g End If If g < 0 And g > -1 Then g = -g g = "-0" & g End If If h > 0 And h < 1 Then h = "0" & h End If If h < 0 And h > -1 Then h = -h h = "-0" & h End If Label?9.Capti?on = "∴x=" & g & "或x=" & h 第五步，得解 End Sub Priva?te Sub Comma?nd4_C?lick() Label?6.Visib?le = False? Label?7.Visib?le = False? Label?8.Visib?le = False? Label?9.Visib?le = False? Line1?.Visib?le = False? Line2?.Visib?le = False? Label?5.Capti?on = "解題區(qū)域" End Sub 以上有些代?碼可能編的?有點傻瓜，因為我也只?是個菜鳥，能達到效果?我就覺得可?以的了。 更重要的是?自己認真的?學(xué)習(xí)一元二?次方程，不能依賴程?序。 感謝讀者的?支持。