学习《数的开方》这一章，要特别注意下面两个问题：一、深刻理解和牢固掌握有关概念1．平方根和算术平方根的概念（1）平方根的概念著一个数的平方等于a，则这个数就叫做a的平方根，就是说，若x2=a，则x叫做a的平方根．例如，2和-2的平方都等于4，所以2和-2都是4的平方根；5和 In the chapter entitled “The Formula of Numbers,” we must pay special attention to the following two issues: First, to deeply understand and firmly grasp the concept. The concept of the square root and the arithmetic square root (1) The concept of the square root is such that the square of a number is equal to a, then this number is called the square root of a, that is, if x2=a, then x is the square root of a. For example, the squares of 2 and -2 are equal to 4, so 2 and -2 are square roots of 4; 5 and