Question

VB用迭代法求X的平方根

平方根的迭代公式为X(n+1)=1\2[X(n)+a\X(n)],通过INPUTBOX输入a的值，并以a作为x的初始值。要求前后两次求出的X的差的绝对值小于0.00001

新人，没分，谢谢各位大虾帮忙！

Answer 1

dim x1!,x2!,a!
a = inputbox("输入")
x2 = a
do
x1= x2
x2=1/2*(x1+a/x1)
loop while abs(x2 - x1) >= 0.00001
msgbox x2

Answer 2

Private Sub Command1_Click()
Dim x1 As Double, x2 As Double, a As Integer
a = Val(InputBox("请输入a", "求a的平方根", ""))
x1 = a
Do
x2 = x1
x1 = 1 / 2 * (x2 + a / x2)
Loop While Abs(x2 - x1) >= 0.00001
Label1.Caption = a & "的平方根约等于" & x1
End Sub

Answer 3

公式带入~