二次函数是反映现实世界中变量间的数量关系和规律的常见数学模型,解决二次函数在实际问题中应用的关键是从实际问题中抽象出数学模型,将实际问题中的数量关系转化为二次函数中的条件后,就可以利用二次函数的图像和性质加以解决。常见题型有两种。 The quadratic function is a common mathematical model that reflects the quantitative relationship and regularity of variables in the real world. The key to solving the practical problem of quadratic function is to abstract the mathematical model from the actual problem and convert the quantitative relationship in the actual problem into After the conditions in the quadratic function, we can use the quadratic function of the image and properties to be solved. There are two common types of questions.