一元二次方程的根的判别式是重要的基础知识,在初中数学中应用极为广泛,它不仅是判别一元二次方程根的情况的依据,而且求代数式值、解方程(组)、求证等式等方面也有着重要的作用,若能熟练掌握它的各种用法,可提高同学们解题能力和知识的综合应用能力。一、判定方程根的情况例1 The discriminant of the root of the one-dimensional quadratic equation is an important basic knowledge. It is widely used in junior high school mathematics. It is not only the basis for judging the root of a quadratic equation, but also the algebraic type value, solution equation (group), verification, etc. The style and other aspects also play an important role. If you are proficient in its various usages, you can improve students’ ability to solve problems and the comprehensive application of knowledge. First, determine the situation of the root of the equation Example 1