First of all, it's clear from the Pythagoras' theorem that a is the square root of ^2 + ^2.

首先,根据毕达哥拉斯定理,勾股定理在西方被称为"毕达哥拉斯定理"

耶鲁公开课 - 基础物理课程节选

I first tested it on the square root of 4 and in one iteration it found 2.

我首先测了下求4的平方根4,它只迭代了一次并返回了2。

麻省理工公开课 - 计算机科学及编程导论课程节选

He was trying to describe electrons, but the theory said there are two roots in the quadratic equation and the second root is mathematically as interesting as the first one.

他当时只是想去描述电子,但是数学理论告诉我们,二次方程有两个根,而第二个根在数学上和第一个根一样有趣

耶鲁公开课 - 基础物理课程节选