首先介绍一下divide and average method
Let A be the number whose square root is wanted. Determine in some way a first guess g of the square root of A. The remaining part of the method is to repeat the following step: Divide A by the current guess g and then average the quotient with g. The average is the new guess.(首先是要对A的平方根做一个估计,我这用x=a/2估计)
Repeat until you have calculated the square root to desired accuracy. Roughly, the number of decimal places doubles with each repetition.
上传了两幅一样的图,竟然删不了,Sorry