《2.3平面向量共线的基本定理.ppt

2.3.1平面向量的基本定理 平面向量基本定理： 课堂练习 课堂小结 1平面向量基本定理的内容 2定理的理解： （1）实数存在唯一性（2）基底的不唯一性 3方程思想在解题中的应用 作业课后：习题5，6 * Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 复习回顾 1. 向量加法与减法有哪几种几何运算法则？ 2.怎样理解向量的数乘运算λa？ （1）|λa|=|λ||a|； （2）λ0时，λa与a方向相同； λ0时，λa与a方向相反； λ=0时，λa=0. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 3.平面向量共线定理是什么？ 非零向量a与向量b共线 存在唯一实数λ，使b＝λa. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 1.如图，光滑斜面上一个木块受到的重力为G，下滑力为F1，木块对斜面的压力为F2，这三个力的方向分别如何？ 三者有何相互关系？ G F1 F2 创设问题情境 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 如图，一盏吊灯，可以由电线CO吊在天花板上, 也可以由电线AO和绳子BO拉住.CO所受的拉力 F应与电灯重力平衡，拉力F分解为AO与BO所 受的拉力 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 归纳：在物理中，力是一个向量，.力可以分解，任何一个大小不为零的力，都可以分解成两个不同方向的分力之和.将这种力的分解拓展到向量中来，向量作为矢量的一般情况，是否也能向两个不同方向分解 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. O C A B M N Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. O C A B M N 质疑：所有的向量都可以由上面的方法得到上面的结果？ 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. 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. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation