2013新人教A版必须修读四2_2(平面向量的线性运算)ppt.ppt

先看一个有趣的规律： 概念深化 问题3：两种法则有什么关系？ 问题4：两个向量的和仍为一个向量，那么和向量的方向与两个向量的方向有何关系？和向量的模与两个向量的模有何关系？ 典例探究 例1（见学案） 问题5：由例1你能得出什么结论？ 向量加法满足交换律和结合律 从而，多个向量的加法可以按照任意的次序与 任意的组合进行 思考： 数学思想 分类讨论 类比、联想 数形结合 高一二部数学组 刘松波 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 相等向量的定义： 共线向量与平行向量的关系： 复习回顾: 长度相等且方向相同的向量叫做相等向量 任一组平行向量都可移到同一条直线上 所以平行向量也叫共线向量 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. V水 大家想一想：如果船不改变方向，他们能否准确及时到出事地点？用所学过的知识加以说明。 河宽4米，水深10米，河水流速为 km/h， 小船以2km/h的速度直向决口处驶去。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 如图，已知向量a,b, 求作向量a+b. B a b C D A A A A 作法:(1)在平面内任取一点A (2)作 则 (3)以AB,AD为邻边作平行四边形ABCD 作平移,共起点,四边形,对角线 平行四边形法则 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 作法（1）在平面内任取一点O o· A B 这种作法叫做向量加法 的三角形法则 （“作平移,首尾连, 由起点指终点”） Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. (1) 同向 (2)反向 A B C A B C 注： Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 从左往右看，“合二为一”