1.试题2016年北京市中学生数学竞赛高中一年级初赛选择第4题出了这样一道题目:例1函数f(x)=x~2+ax+3a的零点都为整数,则a的所有可能值之和等于().(A)-4(B)12(C)4(D)24试题以二次函数为背景考查了函数零点的概念,经过转化变为一个一元二次方程整数解的问题,这种试题在初中各种竞赛中频繁出 1. Test questions 2016 Beijing high school students math contest high school freshmen race to choose the first four questions such a question: Example 1 Function f (x) = x ~ 2 + ax + 3a zero are integers, then all possible a (A) -4 (B) 12 (C) 4 (D) 24 test questions in the background of the quadratic function to examine the concept of the function zero, transformed into a solution of a quadratic equation integer solution Problem, this kind of question frequently appears in every contest of junior high school