函数是中学数学的重要课题．中学数学是怎样讲函数的呢？中学里讲了五种基本初等函数，对每种函数来说，都是首先给出定义及其代表函数，然后作出这些代表函数的图象，根据图象归纳出函数的一般性质，进而是关于这些性质的应用．这个过程说明，图象在中学函数的教学中起着... Function is an important topic in mathematics in middle school. How do middle school mathematics function? There are five elementary elementary functions taught in the middle school. For each function, the definition and its representative function are given first, and then the images of these representative functions are made, the general properties of the function are summed up according to the image, and then Application of these properties. This process shows that images play a role in the teaching of high school functions...