二次根式是算术平方根概念的抽象与扩展,是对实数、代数式等内容的延伸与补充,是学习一元二次方程与解直角三角形的基础.它与方程、不等式、函数等知识有紧密联系,既是重点,也是难点,是中考考点之一.其中热点是考查二次根式的双非性和二次根式的化简.同学们在解这些题目时常出现这样或那样的错误,现总结 The secondary root formula is the abstraction and extension of the concept of arithmetic square root. It is an extension and supplement to real numbers, algebraic expressions, etc. It is the basis for learning the quadratic equations and solving the right triangles. It is closely related to the knowledge of equations, inequalities, and functions. It is one of the key and difficult points in the examination. One of the hot spots is the examination of the two-rooted double-negative and secondary-rooted simplifications. Students often have one or more mistakes in solving these problems.