求在vb中利用格里高利公式求π？

首先昌激，格里简迅裂高利公式为：π/4=1-1/3+1/拦闭5-1/7+……

Option Explicit

Private Sub Form_Click()

Dim a As Double, b As Double, c As Double

a = 1: b = 1: c = 1

Do While b <= 100000

b = b + 2

c = -c

a = a + c / b

Loop

Print "Pi的值为：" &4 * a

End Sub

若要算得更精确，则增加循环次数。

你给的漏咐公式不对！应该是π/2＝2^2/1*3 ×4^2/3*5 ×。。。厅握×（

这个公式求的精度不高！代码扮搜庆如下：

Dim PI1 As Double

Dim PI2 As Double

Dim Temp As Double

Dim n As Double

PI1 = 0: PI2 = 2: n = 2

While PI2 - PI1 >0.000001

PI1 = PI2

Temp = (n * n) / ((n - 1) * (n + 1))

PI2 = PI2 * Temp

n = n + 2

Wend

Me.Text1.Text = PI2

Private Sub Command1_Click()

Dim n, pi,i

pi = 2

n = Val(InputBox("请输入一个数戚孝"))

For i = 1 To n

pi = pi * ((2 * i) ^ 2 / ((2 * i - 1) * (2 * i + 1)))

Next i

MsgBox "π的近似值坦仔没为"让纳 &pi

End Sub

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