用迭代法求某个数的平方根。 已知求平方根的迭代公式为:
代码如下(通过定义一个自定义函数Fsqrt来实现):
Private Function Fsqrt( a As single ) AS single
Dim x0 As Single, x1 As Single
x0 =a/2 '迭代初值
x1 = 0.5*(x0 + a/x0)
Do
x0 = x1 '为下一次迭代作准备
x1 = 0.5*(x0 + a/x0)
Loop While Abs(x1 - x0) > 0.00001
Fsqrt=x1
End Function
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