记不清是哪位数学专家说过,数学复习应遵循十六字原则:“练在复前,复到关键,在练中复,在复中练。”我很赞同这一原则,在自己的教学实践中也向这一原则靠拢。接下来就以二次函数复习为例,谈谈初中数学复习。二次函数与图象是形影不离的,因此以图象为载体来对二次函数进行复习是再恰当不过了。一、练在复前,复到关键下图是二次函数y=ax~2+bx+c(a≠0)的图象的一部分,请根据图象回答下列问题,并说明理由:(1)a___0;(2)b___0;(3) Can not remember which math experts have said that mathematics review should follow the principle of “sixteen words:” “practicing in the complex before the complex key, practicing complex, complex practice.” "I very much agree with this principle, In their own teaching practice also move closer to this principle. Next to the quadratic function review, for example, to talk about junior high school mathematics review. Quadratic functions and images are inseparable, so the image as a carrier to review the quadratic function is quite appropriate. First, the complex before the complex, the key to the complex The following figure is quadratic function y = ax ~ 2 + bx + c (a ≠ 0) part of the image, according to the image to answer the following questions, and explain the reasons: (1 ) a ___ 0; (2) b ___ 0; (3)