走近一次函数把握解题方法

• 作 者: 吴树丽
• 出 处: 中学生数理化(八年级数学)(配合人教社教材)
• 发表日期: 2012年10期

一、掌握概念巧解题例1已知y=(k-2012)x~(|k|-2011)是关于x的正比例函数,试求k的值.分析:由正比例函数的定义,可知|k|-2011=1且k-2012≠0,从而求得k的值.解:由题意得{|k|-2011=1,k-2012≠0,解得k=-2012.温馨提示:在正比例函数y=kx中,不但要使x的指数为1,更不能忽视x的系数k≠0这个条件.二、掌握性质巧解题例2(2012年·衡阳)如图1所示,一次函数

First, grasp the concept of clever solution Example 1 is known y = (k-2012) x ~ (| k | -2011) is a positive proportional function of x, try to find the value of k Analysis: According to the definition of the proportional function, we can see | k = -2011 = 1 and k-2012 ≠ 0, so as to obtain the value of k. Solution: The solution from the title {| k | -2011 = 1, k-2012 ≠ 0, solution k = -2012. : In the proportional function y = kx, not only to make the index of x is 1, but can not ignore the x coefficient k ≠ 0. Second, master the nature of solution Problem 2 (Hengyang 2012) as shown in Figure 1 ,Linear function