命题、定理、证明1ppt课件教学实录

We will continue to improve the company's internal control system, and steady improvement in ability to manage and control, optimize business processes, to ensure smooth processes, responsibilities in place; to further strengthen internal controls, play a control post independent oversight role of evaluation complying with third-party responsibility; to actively make use of internal audit tools detect potential management, streamline, standardize related transactions, strengthening operations in accordance with law. Deepening the information management to ensure full communication "zero resistance". o constantly perfect ERP, and BFS++, and PI, and MIS, and SCM, information system based construction, full integration information system, achieved information resources shared; to expand Portal system application of breadth and depth, play information system on enterprise of Assistant role; to perfect daily run maintenance operation of records, promote problem reasons analysis and system handover; to strengthening BFS++, and ERPand SCM, technology application of training, improve employees application information system of capacity and level. Humanistic care to ensure "zero." To strengthening Humanities care, continues to foster company wind clear, and gas are, and heart Shun of culture atmosphere; strengthening love helped trapped, care difficult employees; carried out style activities, rich employees life; strengthening health and labour protection, organization career health medical, control career against; continues to implementation psychological wrning prevention system, training employees health of character, and stable of mood and enterprising of attitude, created friendly fraternity of Humanities environment. o strengthen risk management, ensure that the business of "zero risk". o strengthened business plans management, will business business plans cover to all level, ensure the business can control in control; to close concern financial, and coal electric linkage, and energy-saving scheduling, national policy trends, strengthening track, active should; to implementation State-owned assets method, further specification business financial management; to perfect risk tube control system, achieved risk recognition, and measure, and assessment, and report, and control feedback of closed ring management, improve risk prevention capacity. To further standardize trading, and strive to achieve "according to law, standardize and fair." Innovation of performance management, to ensure that potential employees "zero fly". To strengthen performance management, process control, enhance employee evaluation and levels of effective communication to improve performance management. To further quantify and refine employee standards ... Work, full play party, and branch, and members in "five type Enterprise" construction in the of core role, and fighting fortress role and pioneer model role; to continues to strengthening "four good" leadership construction 5.3.2命题、定理、证明

教学目的：

1、了解命题的概念，并能区分命题的题设和结论.

2、经历判断命题真假的过程，对命题的真假有一个初步的了解.

3、初步培养学生简单的推理，不同几何语言相互转化的能力. 教学重点：

命题的概念和区分命题的题设与结论. 教学难点：

能区分命题的题设和结论，简单推理证明的过程书写. 教学过程：

一、创设情境，复习导入

教师出示下列问题：

1.平行线的判定方法有哪些?

（定义、平行公理的推论、3个判定定理）

2.平行线的性质有哪些？

学生能积极的思考教师所出示的各个问题，复习巩固有关的知识点，为本节课的学习打下良好的基础.

(注意:平行线的判定方法有三种,另外还有平行公理的推论) 二、尝试活动，探索新知

（1）教师给出下列语句：

①如果两条直线都与第三条直线平行,那么这两条直线也互相平行; ②等式两边都加同一个数,结果仍是等式; lay levels cadres in enterprise development in the of backbone backbone role; to full strengthening members youth work, full play youth employees in company development in the of force role; to improve independent Commission against corruption work level, strengthening on enterprise business key link of effectiveness monitored. , And maintain stability. To further strengthen publicity and education, improve the overall legal system. We must strengthen safety management, establish and improve the education, supervision, and evaluation as one of the traffic safety management mechanism. o conscientiously sum up the Olympic security controls, promoting integrated management to a higher level, higher standards, a higher level of development. Employees, today is lunar calendar on December 24, the ox Bell is about to ring, at this time of year, we clearly feel the pulse of the XX power generation company to flourish, to more clearly hear XX power generation companies mature and symmetry breathing. Recalling past one another across a railing, we are enthusiastic and full of confidence. Future development opportunities, we more exciting fight more spirited. Employees, let us together across 2013 full of challenges and opportunities, to create a green, low-cost operation, full of humane care of a world-class power generation company and work hard! The occasion of the Spring Festival, my sincere wish that you and the families of the staff in the new year, good health, happy, happy!

We will continue to improve the company's internal control system, and steady improvement in ability to manage and control, optimize business processes, to ensure smooth processes, responsibilities in place; to further strengthen internal controls, play a control post independent oversight role of evaluation complying with third-party responsibility; to actively make use of internal audit tools detect potential management, streamline, standardize related transactions, strengthening operations in accordance with law. Deepening the information management to ensure full communication "zero resistance". o constantly perfect ERP, and BFS++, and PI, and MIS, and SCM, information system based construction, full integration information system, achieved information resources shared; to expand Portal system application of breadth and depth, play information system on enterprise of Assistant role; to perfect daily run maintenance operation of records, promote problem reasons analysis and system handover; to strengthening BFS++, and ERPand SCM, technology application of training, improve employees application information system of capacity and level. Humanistic care to ensure "zero." To strengthening Humanities care, continues to foster company wind clear, and gas are, and heart Shun of culture atmosphere; strengthening love helped trapped, care difficult employees; carried out style activities, rich employees life; strengthening health and labour protection, organization career health medical, control career against; continues to implementation psychological wrning prevention system, training employees health of character, and stable of mood and enterprising of attitude, created friendly fraternity of Humanities environment. o strengthen risk management, ensure that the business of "zero risk". o strengthened business plans management, will business business plans cover to all level, ensure the business can control in control; to close concern financial, and coal electric linkage, and energy-saving scheduling, national policy trends, strengthening track, active should; to implementation State-owned assets method, further specification business financial management; to perfect risk tube control system, achieved risk recognition, and measure, and assessment, and report, and control feedback of closed ring management, improve risk prevention capacity. To further standardize trading, and strive to achieve "according to law, standardize and fair." Innovation of performance management, to ensure that potential employees "zero fly". To strengthen performance management, process control, enhance employee evaluation and levels of effective communication to improve performance management. To further quantify and refine employee standards ... Work, full play party, and branch, and members in "five type Enterprise" construction in the of core role, and fighting fortress role and pioneer model role; to continues to strengthening "four good" leadership construction ③对顶角相等; ④如果两条直线不平行,那么同位角不相等. 学生能由教师的引导分析每个语句的特点. 思考：你能说一说这4个语句有什么共同点吗？并能总结出这些语句都是对某一件事情作出“是”或“不是”的判断.初步感受到有些数学语言是对某件事作出判断的. （2）教师给出命题的定义：

判断一件事情的语句,叫做命题. （3）命题的组成和形式：

①命题由题设和结论两部分组成.题设是已知事项,结论是由已知事项推出的事项. ②命题的形成，可以写成“如果……，那么……”的形式. （4）真命题与假命题：

教师出示问题：

①如果两个角相等，那么它们是对顶角. ②如果a＞b，b＞c那么a＞c. ③如果两个角互补，那么它们是邻补角. 学生能根据命题的题设和结论，判断出命题的真或假. 三、尝试反馈，理解新知

定理与证明：

命题的正确性是我们经过推理证实的，这样得到的真命题叫做定理.

作为真命题，定理也可以作为继续推理的依据. lay levels cadres in enterprise development in the of backbone backbone role; to full strengthening members youth work, full play youth employees in company development in the of force role; to improve independent Commission against corruption work level, strengthening on enterprise business key link of effectiveness monitored. , And maintain stability. To further strengthen publicity and education, improve the overall legal system. We must strengthen safety management, establish and improve the education, supervision, and evaluation as one of the traffic safety management mechanism. o conscientiously sum up the Olympic security controls, promoting integrated management to a higher level, higher standards, a higher level of development. Employees, today is lunar calendar on December 24, the ox Bell is about to ring, at this time of year, we clearly feel the pulse of the XX power generation company to flourish, to more clearly hear XX power generation companies mature and symmetry breathing. Recalling past one another across a railing, we are enthusiastic and full of confidence. Future development opportunities, we more exciting fight more spirited. Employees, let us together across 2013 full of challenges and opportunities, to create a green, low-cost operation, full of humane care of a world-class power generation company and work hard! The occasion of the Spring Festival, my sincere wish that you and the families of the staff in the new year, good health, happy, happy!

We will continue to improve the company's internal control system, and steady improvement in ability to manage and control, optimize business processes, to ensure smooth processes, responsibilities in place; to further strengthen internal controls, play a control post independent oversight role of evaluation complying with third-party responsibility; to actively make use of internal audit tools detect potential management, streamline, standardize related transactions, strengthening operations in accordance with law. Deepening the information management to ensure full communication "zero resistance". o constantly perfect ERP, and BFS++, and PI, and MIS, and SCM, information system based construction, full integration information system, achieved information resources shared; to expand Portal system application of breadth and depth, play information system on enterprise of Assistant role; to perfect daily run maintenance operation of records, promote problem reasons analysis and system handover; to strengthening BFS++, and ERPand SCM, technology application of training, improve employees application information system of capacity and level. Humanistic care to ensure "zero." To strengthening Humanities care, continues to foster company wind clear, and gas are, and heart Shun of culture atmosphere; strengthening love helped trapped, care difficult employees; carried out style activities, rich employees life; strengthening health and labour protection, organization career health medical, control career against; continues to implementation psychological wrning prevention system, training employees health of character, and stable of mood and enterprising of attitude, created friendly fraternity of Humanities environment. o strengthen risk management, ensure that the business of "zero risk". o strengthened business plans management, will business business plans cover to all level, ensure the business can control in control; to close concern financial, and coal electric linkage, and energy-saving scheduling, national policy trends, strengthening track, active should; to implementation State-owned assets method, further specification business financial management; to perfect risk tube control system, achieved risk recognition, and measure, and assessment, and report, and control feedback of closed ring management, improve risk prevention capacity. To further standardize trading, and strive to achieve "according to law, standardize and fair." Innovation of performance management, to ensure that potential employees "zero fly". To strengthen performance management, process control, enhance employee evaluation and levels of effective communication to improve performance management. To further quantify and refine employee standards ... Work, full play party, and branch, and members in "five type Enterprise" construction in the of core role, and fighting fortress role and pioneer model role; to contnues to strengthening "four good" leadership construction 在很多情况下，一个命题的正确性需要经过推理才能作出判断，这个推理过程叫做证明. 老师出示书21页例2，分析并板书过程. 试一试：

1.“等式两边乘同一个数，结果仍是等式”是命题吗？它们题设和结论分别是什么？

2.命题“两条平行线被第三第直线所截，同位角相等”是正确的吗？

3.命题“如果两个角互补，那么它们是邻补角”是正确的吗？

再举出一些命题的例子，判断它们是否正确.（小组互相检查）

四、总结知识，拓展补充：

教师引导学生完成本节课的小结，强调重要的知识点. 五、布置作业：

练习（P21）第1、2题；

习题5.3第6、12题. 六、教学反思：

lay levels cadres in enterprise development in the of backbone backbone role; to full strengthening members youth work, full play youth employees in company development in the of force role; to improve independent Commission against corruption work level, strengthening on enterprise business key link of effectiveness monitored. , nd maintain stability. To further strengthen publicity and education, improve the overall legal system. We must strengthen safety management, establish and improve the education, supervision, and evaluation as one of the traffic safety management mechanism. o conscientiously sum up the Olympic security controls, promoting integrated management to a higher level, higher standards, a higher level of development. Employees, today is lunar calendar on December 24, the ox Bell is about to ring, at this time of year, we clearly feel the pulse of the XX power generation company to flourish, to more clearly hear XX power generation companies mature and symmetry breathing. Recalling past one another across a railing, we are enthusiastic and full of confidence. Future development opportunities, we more exciting fight more spirited. Employees, let us together across 2013 full of challenges and opportunities, to create a green, low-cost operation, full of humane care of a world-class power generation company and work hard! The occasion of the Spring Festival, my sincere wish that you and the families of the staff in the new year, good health, happy, happy!