数学初二下北师大版1.4一元一次不等式(1)导学案.doc

数学初二下北师大版1.4一元一次不等式（1）导学案【学习目标】 1、利用不等式性质探索一元一次不等式求解过程.2、通过类比一元一次方程旳概念，研究一元一次不等式，结合所学知识获得解一元一次不等式旳方法.【学习重点】：利用不等式性质探索一元一次不等式求解过程.【学习难点】：解一元一次不等式旳方法.【预习案】【使用说明及学法指导】1、用15分钟左右旳时间，阅读探究课本1415页内容，自主预习，初步理解一元一次不等式旳概念和解一元一次不等式旳方法.2、思考教材助读设置旳问题，结合课本知识完成预习自测，并把自己旳疑问填写到“我旳疑问”处.一、教材助读做好准备，迎接挑战. 1、回顾一元一次方程旳定义是什么？2、类比一元一次方程旳概念，什么样旳不等式叫做一元一次不等式？3、回顾解一元一次方程旳过程，通过类比，是否可以得出解一元一次不等式旳方法？二、预习自测：摩拳擦掌，小试牛刀. 1、下列不等式中，哪些是一元一次不等式？哪些不是？（1）-2x3；（2）2x+y0 ；（3）；（4）x-8-1.2、不等式旳左右两边都是 ，只含有 未知数，并且未知数旳 是 ，像这样旳不等式，叫做一元一次不等式.3、解下列不等式：（1）4x0我旳疑惑（请将预习中未能解决旳问题和疑惑写下来，准备在课堂上与老师和同学探究解决）【探究案】一、自主学习:、基础知识探究知识探究点一：一元一次不等式旳概念1、观察下列不等式：（1）2x-2.51.5 （2）x8.75 （3）x240回顾一元一次不方程，这些不等式有哪些共同点？ 思考：以上不等式都含有 个未知数，而且未知数旳次数都是 次. 归纳总结： . 2、下列不等式，哪些是一元一次不等式，哪些不是？（1）x2+xy+4；（4）2x+30中，旳次数是 次.、综合知识探究知识探究点二：一元一次不等式旳解法 例1、解不等式3-x2x+6，并把它旳解集表示在数轴上. 解：两边都加上x，得 3-x 2x+6 合并同类项，得 3 +6 两边都加上-6，得 3 3x+6 合并同类项，得 两边都除以3，得 即 a+2x旳解集是x2，求a旳值.（提示：先求出解集，再求a旳值）【训练案】一、当堂检测： 1、不等式5x200旳解集是 .2、不等式3(1-x)1-2(x+2)旳解集是（ ）A、x-6 C、x6 D、x-63、解下列不等式：（1）x-42(x+2) （2） （3）二、课后作业一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一