教材是如何作出函数图像的呢?下面以作函数y=2x图像的为例来说明。例1沪科版数学八年级上册第26页:对于自变量x的每一个确定的值,可以得出对应函数y的唯一值。列表如下:例2沪科版数学九年级上册第6页:画出二次函数y=x~2的图像。解:列表,由于自变量x可以取任意实数,因此以0为中心选x的一些值列表: How to make a function of the text of the image? Here to illustrate the function y = 2x image as an example. Example 1 Shanghai Second Edition of Mathematics eighth grade on the first page 26: for each of the x variables for the determination of the value, you can get the corresponding value of the y function. The list is as follows: Example 2 Shanghai college mathematics ninth grade on the first six pages: draw quadratic function y = x ~ 2 images. Solution: The list, because the argument x can take any real number, so a list of some values ​​of x centered at 0: