在近几年中考函数试题中,经常遇到一类问题:给出一个表格,让学生根据里面的数据判断是哪一种函数,很多学生遇到这类问题,有的束手无策,不知如何判断,有的是采用建立坐标系,利用描点连线来判断,这样不但费时,而且也极易出错.那么怎样才能快速判断是什么函数呢?下面我告诉大家一个简单的方法:若表格中x和y的乘积不变,那么就是反比例函数,若x变化相同的数时,y中的数据也变化的相同,那么就一定是一次函数,因为题目要求你只在三种函数,即一次函数、二次函数、反比例函数中选择,所以,若通过我们 In the examination test function questions in recent years, we often encounter a class of questions: give a table, let students determine which function is based on the data inside, many students encounter such problems, some helpless, I do not know how to judge, Some use the establishment of a coordinate system, using the drawing point connection to determine, this is not only time-consuming, but also very easy to error. So how can we quickly determine what is the function? Here I tell you a simple way: If the table x and y product No change, then it is an inverse proportional function. If the x changes by the same number, the data in y will also change the same, then it must be a function, because the topic requires you only in three kinds of functions, that is, a function, a quadratic function, Inverse function is selected, so if we pass through