给排水工程计算机应用课后习题.docVIP

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0Private 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