技法专题第2讲分类讨论思想、转化与化归思想课件

1、Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.分类讨论思想在解题中的应用1由数学概念而引起的分类讨论：如绝对值的定义、不等式的定义、二次函数的定义、直线的倾斜角等 2由数学运算要求而引起的分类讨论：如除法运算中除数不为零，偶次方根为非负数，对数运算中真数与底数的要求，指数运算中底数的要求，不等式中两边同乘以一个正数、负数，三角函数的定义域，等比数列an的前n项和公式等 3由性质、定理、公式的限制而引起的分类讨论：如

2、函数的单调性、基本不等式等 4由图形的不确定性而引起的分类讨论：如二次函数图象、指数函数图象、对数函数图象等 5 由参数的变化而引起的分类讨论：如某些含有参数的问题，由于参数的取值不同会导致所得的结果不同，或者由于对不同的参数值要运用不同的求解或证明方法等. Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5

3、Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation onl

4、y.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyrig

5、ht 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides f

6、or .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Ev

7、aluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2

8、.0.0.Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Asp

9、ose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspos

10、e Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.转化与化归思想在解题中的应用1在三角函数中，涉及到三角式的变形，一般通过转化与化归将复杂的三角问题转化为已知或易解的三角问题，以起到化暗为明的作用，主要的方法有公式的“三用”(顺用、逆用、变形用)、角度的转化、函数的转化等 2换元法：是将一个复杂的或陌生的函数、方程、不等式转化为简单的或熟悉的函数、方程、不等式的一种重要的方法 Evaluation

11、only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.转化与化归思想在解题中的应用3在解决平面向量与三角函数、平面几何、解析几何等知识的交汇题目时，常将平面向量语言与三角函数、平面几何、解析几何语言进行转化 4在解决数列问题时，常将一般数列转化为等差数列或等比数列求解 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright

12、2019-2019 Aspose Pty Ltd.转化与化归思想在解题中的应用5在利用导数研究函数问题时，常将函数的单调性、极值(最值)、切线问题，转化为其导函数f(x)构成的方程、不等式问题求解 6 在解决解析几何、立体几何问题时，常常在数与形之间进行转化. Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5

13、 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation on

14、ly.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyri

15、ght 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile .Copyright 2019-2019 Asp