函数的奇偶性是函数的重要性质,教材中是先从日常生活中的诸多对称现象来唤起研究函数对称性的意识.接着用两个熟悉的函数f(x)=x~2与f(x)=-1/x(x≠0)的图象为引例,直观地刻画出函数图象的两种特殊的对称性:前者关于y轴对称,后者关于原点对称.以此为情境按特殊到一般的思维方式提出本课的研究课题:怎样用数量关系来刻画函数图象的这种对称性?一、优化步骤,杜绝出错,让学生运用起来更顺手 The function’s parity is the important function of the function. In the textbook, we first arouse the consciousness of the symmetry of the research function from many symmetrical phenomena in daily life.Then we use two familiar functions f (x) = x ~ 2 and f ) = - 1 / x (x ≠ 0) as an example to visually depict two special symmetries of the function image: the former is symmetrical about the y axis and the latter is symmetric about the origin. To the general way of thinking put forward the subject of this lesson: how to use the number of relations to characterize the symmetry of the function image? First, the optimization steps to eliminate mistakes, so that students can use it more smoothly