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'　π／4 = 1 - 1/3 +1/5 - 1/7 + …… + (-1)^(n-1)/(2*n-1)
Function Pai(n)
Dim i
Pai = 1e-30
For i = 1 To n
Pai = Pai + (-1)^(i - 1) / (2 * i - 1)
Next
End Function
Dim Pi, i, dx, C
dx = 1: Pi = 0: i = 0
Do While Abs(dx) > 1e-8
i = i + 1
dx = (-1)^(i - 1) / (2 * i - 1)
Pi = Pi + dx
Loop
Pi = 4 * Pi
C = "π= [1 - 1/3 +1/5 - 1/7 + …… + "
C = C & "(-1)^(n-1)/(2n-1)]×4" & vbCrLf
C = C & "　= " & Pi & vbCrLf & vbCrLf
C = C & "n = " & i & vbCrLf & vbCrLf
C = C & "误差dx = " & Abs(dx)
MsgBox C, 0 + 64, "计算结果"
'　将以上代码复制后，粘贴到一个新建的文本文档中；
'　存盘退出后，改其文件名为【计算π.VBS】；
'　在 Windows 中直接双击这个文件即可运行。
'　n = 50000001
'　dx = 9.9999999E-09
'　π= 3.14159267359025