给水排水工程计算机应用课后答案,给排水工程计算机应用课后习题

13、Private Sub Form_Click()

Dim x, x0 As Double

Dim n As Integer

x = 0: n = 0

Do

x1 = (5 + 2 * x) ^ (1 / 3)

n = (n + 1)

x2 = x: x = x1

Loop Until Abs(x2 - x) < 0.001

Print x

End Sub

15、Private Sub Command1_Click()

Dim x, y, a, b

y0 = 12.119

a = -1: b = 8

x = (a + b) / 2

y = x ^ 4 - 7.223 * x ^ 3 + 13.447 * x ^ 2 - 0.672 * x - 10.223

If y * y0 > 0 Then

a = x

Else

b = x

end if

Do Until Abs(a - b) < 10 ^ (-6)

Loop

Text1.Text = x

Print x

End Sub

16题参考Private Sub Form_Click()

Dim x As Double: Dim y As Double: Dim n As Integer: Dim h As Integer

For h = 1 To 1000

x = 1 / 1000

y = y + x * (0 + x * h)

Next h

Print y

End Sub

Private Sub Form_Click()

Dim x As Double, y As Double, s As Double

For x = 0 To 1 Step 0.00001

y = x

s = s + y * 0.00001

Next

Print s

End Sub

正式

答案

矩形法0.359174735226714

Private Sub Form_Click()

Dim x, y, h, a, b As Double

x = 1 / 10000

y = 0

For h = 1 To 10000

b = h * x

a = b * 2.71828 ^ b / (1 + b) ^ 2

y = y + x * a

Next

Print y

End Sub

梯形法0.35914073

Private Sub Form_Click()

Dim h, y, a, b, c

h = 1 / 1000

y = 2.71828 / 8

For b = 1 To 1000 - 1

a = b * h

c = a * 2.71828 ^ a / (1 + a) ^ 2

y = y + c

Next

y = h * y

Print y

End Sub

抛物线法0.3589142

Private Sub Form_Click()

Dim h, y, a, b, c, d, f, g, i

h = 1 / (1000 * 2)

a = (2 * h) * (1000 - 1) + 0

c = a * 2.71828 ^ a / (1 + a) ^ 2

y = 2.71828 / 4 + 4 * c

For b = 1 To 1000 - 1

d = 0 + 2 * b * h

f = d * 2.71828 ^ d / (1 + d) ^ 2

g = 0 + 2 * (b - 1) * h

i = g * 2.71828 ^ g / (1 + g) ^ 2

y = y + 2 * f + 4 * i

Next

y = y * h / 3

Print y

End Sub

17、答案 矩形法5.056198

Private Sub Form_Click()

Dim x, y, h, a, b As Double

x = 3.1415926535 / 10000

y = 0

For h = 1 To 10000

b = h * x

a = Log(5 - 4 * cosb)

y = y + x * a

Next

Print y

End Sub

抛物线法 5.056506086

Private Sub Form_Click()

Dim h, y, a, b, c As Double

h = 3.1415926535 / (1000 * 2)

a = 2 * h * (1000 - 1) + 0

c = Log(5 - 4 * cosa)

y = Log(5 - 4 * cos0) + Log(5 + -4 * Cos(3.1415926535)) + 4 * c

For b = 1 To 1000 - 1

d = 0 + 2 * b * h

f = Log(5 - 4 * cosd)

g = 0 + 2 * (b - 1) * h

i = Log(5 - 4 * cosg)

y = y + 2 * f + 4 * i

Next

y = y * h / 3

Print y

End Sub

第二小题抛物线法 3.02299894

Private Sub Form_Click()

Dim h, y, a, b, c As Double

h = 3.1415926535 / (1000 * 2 * 2)

a = 2 * h * (1000 - 1) + 0

c = sina / (1 - 0.25 * sina * sina) ^ 0.5

y = sin0 / (1 - 0.25 * sin0 * sin0) ^ 0.5 + Sin(3.14159265 / 2) / (1 - 0.25 * Sin(3.14159265 / 2) * Sin(3.14159265 / 2)) ^ 0.5 + 4 * c

For b = 1 To 1000 - 1

d = 0 + 2 * b * h

f = sind / (1 - 0.25 * sind * sind) ^ 0.5

g = 0 + 2 * (b - 1) * h

i = sing / (1 - 0.25 * sing * sing) ^ 0.5

y = y + 2 * f + 4 * i

Next

y = y * h / 3

Print y

End Sub

矩形法

Private

Sub Form_Click()

Dim x, y, h, a, b As Double

x = 3.14159 / 200

y = 0

For h = 1 To 100

b = h * x

a = sinb / (1 - 0.25 * sinb * sinb) ^ 0.5