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1、精品教学教案5 简单的幂函数教学目标:1了解指数是整数的幂函数的概念;2学会利用定义证明简单函数的奇偶性,了解用函数的奇偶性画函数图象和研究函数的方法;3培养学生从特殊归纳出一般的意识,培养学生利用图像研究函数奇偶性的能力。重点难点:1教学重点:幂函数的概念,奇偶函数的概念.2教学难点:幂函数图像性质,研究函数奇偶性。教学过程:一、情景引入(1)如果张红买了每千克1 元的蔬菜x千克,那么她需要支付yx(2)如果正方形的边长为x,那么正方形的面积2yx(3)如果立方体的边长为x,那么立方体的体积3yx(4)如果正方形的面积为x,那么正方形的边长yx(5)如果某人x秒内骑车行进 1 千米那么他骑车
2、的平均速度1yx以上问题中的函数有什么共同特征?yx2yx3yxyx12()yx1yx1()yx答:底数是自变量x,只是指数不同.二、知识探究学习资料总结-名师归纳欢迎下载-欢迎下载 名师归纳-第 1 页,共 4 页 -精品教学教案1、幂函数的定义:如果一个函数,底数是自变量x,指数是常量,即yx(是常数),这样的函数叫幂函数.具体特点:底数是自变量指数是常量x的系数是 1 判一判:判断下列函数是否为幂函数.(1)myax2(2)yxx3nyx()5(4)(2)yx2(5)2yx21(6)yx仅(3)是幂函数2、画出函数3yx的图像,讨论其图像特征(单调性、对称性等)解:列表:x2112012
3、12y811801818描点连线:图像特征:单调性:在 R 上是增加的对称性:函数图像 关于原点对称并且对任意 x,33fxxxfx即fxfx,像这样的函数叫作奇函数奇函数的特点:定义域关于原点对称对于定义域中的任意的x,都有fxfx、观察函数2fxx,讨论图像特征函数图像关于y轴对称,并且对任意x,22fxxxfxxyo1xyo1-1-1学习资料总结-名师归纳欢迎下载-欢迎下载 名师归纳-第 2 页,共 4 页 -文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2
4、J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V
5、9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I
6、9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:C
7、V2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV
8、6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH1
9、0I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码
10、:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1精品教学教案即fxfx,像这样的函数叫作偶函数偶函数的特点:定义域关于原点对称对于定义域中的任意的x,都有fxfx注:如果函数()yf x是奇函数或偶函数,我们就说函数()yfx具有奇偶性;根据奇偶性可将函数分为四类:奇函数、偶函数、既是奇函数又是偶函数、既不是奇函数也不是偶函数;注意:“任意”、“都有”等关键词,奇偶性是函数的整体性奇函数的图像关于原点对称,偶函数的图像关于y轴对称;奇、偶函数的定义域关于“0”对称如果一个函数的定义域不关
11、于“0”对称,则该函数既不是奇函数也不是偶函数;三、典型例题例 2 判断52fxx和4()2g xx的奇偶性.【课本 49 页动手实践】四、课堂训练1、画出下列函数的图像,判断其奇偶性.3(1)yx2(2)yx,x(3,3 2(3)yx32(4)y2(x1)12、判断函数()yf x在定义域R 上是奇函数,且在,0上是增加的的,则()f x在0,上也是增加的.(正确)函数()yf x在定义域R 上是偶函数,且在,0上是减少的,则()f x在0,上也是减少的.(错误)3、已知奇函数()fx,则()f ab,()fa=.已知偶函数()fx,则()f ab,()fa=.学习资料总结-名师归纳欢迎下载
12、-欢迎下载 名师归纳-第 3 页,共 4 页 -文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 Z
13、H10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档
14、编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A
15、4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6
16、 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1
17、文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B
18、8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1精品教学教案4、二次函数2(1)23fxmxmx是偶函数,则fx在,0上是5、设()fx为 定 义在 R 上的偶 函数,且()fx在0,上是 增加 的,则(2),(3),(4)fff由小到大的排列顺序为五、小结1.几
19、种简单幂函数的图像及性质.2.判断函数奇偶性的方法:(1)图像法图像关于原点对称()yf x是奇函数.图像关于 y 轴对称()yf x是偶函数.(2)解析法fxfx()yfx为奇函数fxfx()yf x为偶函数六、补充1、常见幂函数图像(右图)2、总结幂函数性质所有的幂函数在0,都有定义,并且图象都过点1,1(原因:11x);0a时,幂函数的图象都通过原点,且在0,上,是增函数(从左往右看,函数图象逐渐上升).0a时,幂函数的图象在区间0,上是减函数.在第一家限内,当x向原点靠近时,图象在y轴的右方无限逼近y轴正半轴,当x慢慢地变大时,图象在x轴上方并无限逼近x轴的正半轴.0 学习资料总结-名
20、师归纳欢迎下载-欢迎下载 名师归纳-第 4 页,共 4 页 -文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B
21、3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H
22、6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2
23、J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V
24、9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I
25、9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1文档编码:CV2J4R3B8A4 HV6V9B3U7X6 ZH10I9H6F1O1
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