专题2第7讲三角函数模型与解三角形的实际应用.ppt

Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 专题二 三角变换与平面向量、 复数 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. 一、三角函数图象的应用 例1已知某海滨浴场的海浪高度y(米)是时间t(0≤t≤24，单位：小时)的函数，记作y=f(t)．下表是某日各时的浪高数据： 经过长期观测，y=f(t)的曲线可近似地看成是函数y=Acosωt+b的图象． t(时) y(米) 0 1.5 3 1.0 6 0.5 9 1.0 12 1.5 15 1.0 18 0.5 21 0.99 24 1.5 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. (1)根据以上数据，求出函数y=Acosωt+b的最小正周期T、振幅A及函数表达式； (2)依据规定，当海浪高度高于1米时才对冲浪爱好者开放．请根据(1)的结论，判断一天内的上午8：00至晚上20：00之间，有多少时间可供冲浪爱好者进行运动？ 【分析】读取与分析表中的数据，求得模型后，把第(2)问的情景转化为一个简单的三角函数不等式，再运用整体思想，借助函数的图象或者单位圆可以求解． 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 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.