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1、名师精编优秀教案任意角的三角函数教学目的:知识目标:1.复习三角函数的定义、定义域与值域、符号、及诱导公式;2.利用三角函数线表示正弦、余弦、正切的三角函数值;3.利用三角函数线比较两个同名三角函数值的大小及表示角的范围。能力目标:掌握用单位圆中的线段表示三角函数值,从而使学生对三角函数的定义域、值域有更深的理解。德育目标:学习转化的思想,培养学生严谨治学、一丝不苟的科学精神;教学重点:正弦、余弦、正切线的概念。教学难点:正弦、余弦、正切线的利用。授课类型:新授课教学模式:讲练结合教具:多媒体、实物投影仪教学过程:一、复习引入:1三角函数的定义及定义域、值域:练习 1:已知角的终边上一点(3,
2、)Pm,且2sin4m,求cos,sin的值。解:由题设知3x,ym,所以2222|(3)rOPm,得23rm,从而2sin4m23mmrm,解得0m或216625mm当0m时,3,3rx,cos1,tan0 xyrx;当5m时,2 2,3rx,615cos,tan43xyrx;当5m时,2 2,3rx,615cos,tan43xyrx2三角函数的符号:练习 2:已知sin0且tan0,(1)求角的集合;(2)求角2终边所在的象限;(3)试判断tan,sincos222的符号。3诱导公式:练习 3:求下列三角函数的值:(1)9cos4,(2)11tan()6,(3)9sin2二、讲解新课:当角
3、的终边上一点(,)P x y的坐标满足221xy时,有三角函数正弦、余弦、正切值的几何表示三角函数线。名师精编优秀教案1单位圆:圆心在圆点O,半径等于单位长的圆叫做单位圆。2有向线段:坐标轴是规定了方向的直线,那么与之平行的线段亦可规定方向。规定:与坐标轴方向一致时为正,与坐标方向相反时为负。3三角函数线的定义:设任意角的顶点在原点O,始边与x轴非负半轴重合,终边与单位圆相交与点P(,)x y,过P作x轴的垂线,垂足为M;过点(1,0)A作单位圆的切线,它与角的终边或其反向延长线交与点T.由四个图看出:当角的终边不在坐标轴上时,有向线段,OMx MPy,于是有sin1yyyMPr,cos1xx
4、xOMr,tanyMPATATxOMOA我们就分别称有向线段,MP OM AT为正弦线、余弦线、正切线。说明:三条有向线段的位置:正弦线为的终边与单位圆的交点到x轴的垂直线段;余弦线在x轴上;正切线在过单位圆与x轴正方向的交点的切线上,三条有向线段中两条在单位oxyMTPAoxyMTPAxyoMTPAxyoMTPA()()()()文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2
5、Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8
6、M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1
7、F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4
8、L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI
9、8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H
10、10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档
11、编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3名师精编优秀教案圆内,一条在单位圆外。三条有向线段的方向:正弦线由垂足指向的终边与单位圆的交点;余弦线由原点指向垂足;正切线由切点指向与的终边的交点。三条有向线段的正负:三条有向线段凡与x轴或y轴同向的为正值,与x轴或y轴反向的为负值。三条有向线段的书写:有向线段的起点字母在前,终点字母在后面。4例题分析:例 1作出下列各角的正弦线、余弦线、正切线。(1)3;(2)56;(3)23;(4)136解:图略。例 2.利用三角函数线比较下
12、列各组数的大小:132sin与54sin 2tan32与 tan54 3cot32与 cot54解:如图可知:32sin54sintan32 tan54cot32cot54例 4利用单位圆写出符合下列条件的角x的范围。A B o T2 T1 S2S1 P2 P1 文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3
13、文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:C
14、P2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5
15、J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 H
16、P1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1
17、D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10
18、ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I
19、2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3名师精编优秀教案(1)1sin2x;(2)1cos2x;(3)10,sin2xx且1cos2x;(4)1|cos|2x;(5)1sin2x且tan1x答案:(1)71122,66kxkkZ;(2)22,66kxkkZ;(3)5,36xkZ;(4),6262kxkkZ;(5)322,24kxkkZ三、巩固与练习四、小结:本节课学习了以下内容:1三角函数线的定义;2会画任意角的三角函数线;3利用单位圆比较三角函数值的大小,求角的范围。文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8
20、I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J
21、3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:
22、CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F
23、5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8
24、HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R
25、1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3文档编码:CP2Z8F5J8M8 HP1F4R1D4L10 ZI8G8I2H10J3