同学们已经学过了一次函数.在初二的下学期,大家还将学到形如y=1/x,y=-3/x一类的函数(图1、图2),也就是所谓的反比例函数.到了初三时,大家将会系统地研究二次函数.y=x~2,y=1-3x~2,y=x~2/2+x/2-1都是二次函数(图3、图4、图5).在高中阶段,大家还会接触到指数函数,比如y=2~x(图6). The students have already learned a function. In the second semester of the second year, you will also learn functions such as y=1/x and y=-3/x (Figure 1, Figure 2). The inverse proportion function. By the third year, we will systematically study the quadratic function. Y=x~2, y=1-3x~2, y=x~2/2+x/2-1 are quadratic Functions (Fig. 3, Fig. 4, Fig. 5). In high school, you will also be exposed to exponential functions, such as y=2~x (Figure 6).