《正弦定理和余弦定理 复习课件.ppt

目录 第7课时　正弦定理和余弦定理 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 2014高考导航 考纲展示 掌握正弦定理、余弦定理，并能解决一些简单的三角形度量问题. 备考指南 1.利用正、余弦定理求三角形中的边、角及其面积问题是高考考查的热点. 2.常与三角恒等变换相结合，综合考查三角形中的边与角、三角形形状的判断等. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 本节目录 教材回顾夯实双基 考点探究讲练互动 名师讲坛精彩呈现 知能演练轻松闯关 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 教材回顾夯实双基 基础梳理 正弦定理和余弦定理 b2＋c2－2bccosA c2＋a2－2cacosB a2＋b2－2abcosC Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 2RsinA 2RsinB 2RsinC sinA∶sinB∶sinC Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 思考探究 在△ABC中，“sin Asin B”是“AB”的什么条件？ Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 课前热身 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. 5.在△ABC中，B＝60°，b2＝ac，则△ABC的形状为________． 解析：由余弦定理得b2＝a2＋c2－2accos 60°＝ac， 即a2－2ac＋c2＝0，∴a＝c. 又B＝60°，∴△ABC为等边三角形． 答案：等边三角形 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 考点探究讲练互动 例1 考点突破 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. 【规律小结】　(1)应熟练掌握正、