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1、3.2图形的平移(二)第三章图形的平移与旋转沽源县第三中学张秀荣123456780–1–2–3–4–512349105在直角坐标系中描出以下各点:(0,0)(5,4)(3,0)(5,1)(5,-1)(3,0)(4,-2)(0,0)并用线段依次连接,看一看是什么图案.yx123456780–1–2–3–4–512349105图中的鱼是将坐标为:(0,0)(5,4)(3,0)(5,1)(5,-1)(3,0)(4,-2)(0,0)的点用线段依次连接而成的将这条“鱼”向右平移5个单位长度。(1)画出平移后的新“鱼”(2)在图中尽量多选几组对应点,并将他们的坐标填入表中(3)你发现对应点
2、的坐标之间有什么关系?yx(x,y)(0,0)(5,4)(3,0)(5,1)(5,-1)(3,0)(4,-2)(0,0)(x+5,y)(5,0)(10,4)(8,0)(10,1)(10,-1)(8,0)(9,-2)(5,0)纵坐标保持不变,将各坐标的横坐标都加5123456780–1–2–3–4–512349105图中的鱼是将坐标为:(0,0)(5,4)(3,0)(5,1)(5,-1)(3,0)(4,-2)(0,0)的点用线段依次连接而成的。将这条“鱼”向左平移3个单位长度呢?你发现对应点的坐标之间有什么关系?yx-1-2(x,y)(0,0)(5,4)(3,0)(5,1)(5,
3、-1)(3,0)(4,-2)(0,0)(x-3,y)(-3,0)(2,4)(0,0)(2,1)(2,-1)(0,0)(1,-2)(-3,0)纵坐标保持不变,将各坐标的横坐标都减3123456780–1–2–3–4–512345图中的鱼是将坐标为:(0,0)(5,4)(3,0)(5,1)(5,-1)(3,0)(4,-2)(0,0)的点用线段依次连接而成的将这条“鱼”向上平移2个单位长度呢?你发现对应点的坐标之间有什么关系?yx猜一猜横坐标保持不变,将各坐标的纵坐标都加2123456780–1–2–3–4–512345图中的鱼是将坐标为:(0,0)(5,4)(3,0)(5,1)(5
4、,-1)(3,0)(4,-2)(0,0)的点用线段依次连接而成的将这条“鱼”向下平移1个单位长度呢?你发现对应点的坐标之间有什么关系?yx猜一猜横坐标保持不变,将各坐标的纵坐标都减1、看谁反应快?1、在平面直角坐标系中,有一点P(-5,3)若将P:(1)向左平移2个单位长度,所得点的坐标为______;(2)向右平移3个单位长度,所得点的坐标为______;(3)向下平移4个单位长度,所得点的坐标为______;(4)向上平移3个单位长度,所得点的坐标为_______。考考你(-7,3)(-2,3)(-5,-1)(-5,6)123456780–1–2–3–4–512349105
5、图中的鱼是将坐标为:(0,0)(5,4)(3,0)(5,1)(5,-1)(3,0)(4,-2)(0,0)的点用线段依次连接而成的则坐标变化为:纵坐标保持不变,将各坐标的横坐标加4又会怎样?yx原图形被向右平移4个单位(x,y)(0,0)(5,4)(3,0)(5,1)(5,-1)(3,0)(4,-2)(0,0)(x+4,y)(4,0)(9,4)(7,0)(9,1)(9,-1)(7,0)(8,-2)(4,0)123456780–1–2–3–4–512349105图中的鱼是将坐标为:(0,0)(5,4)(3,0)(5,1)(5,-1)(3,0)(4,-2)(0,0)的点用线段依次连接
6、而成的则坐标变化为:纵坐标保持不变,将各坐标的横坐标减2,图案会变成什么样?yx-1-2原图形被向左平移2个单位(x,y)(0,0)(5,4)(3,0)(5,1)(5,-1)(3,0)(4,-2)(0,0)(x-2,y)(-2,0)(3,4)(1,0)(3,1)(3,-1)(1,0)(2,-2)(-2,0)123456780–1–2–3–4–512345图中的鱼是将坐标为:(0,0)(5,4)(3,0)(5,1)(5,-1)(3,0)(4,-2)(0,0)的点用线段依次连接而成的横坐标保持不变,将各坐标的纵坐标都加2,则原图型变为什么样?yx猜一猜原图形被向上平移2个单位123
7、456780–1–2–3–4–512345图中的鱼是将坐标为:(0,0)(5,4)(3,0)(5,1)(5,-1)(3,0)(4,-2)(0,0)的点用线段依次连接而成的横坐标保持不变,将各坐标的纵坐标都减1,则原图型变为什么样?yx猜一猜原图形被向下平移1个单位考考你比一比,看谁反应快?2、如果A,B的坐标分别为A(-4,5),B(-4,2),将点A向___平移___个单位长度得到点B;将点B向___平移___个单位长度得到点A。3、如果P、Q的坐标分别为P(-3,-5),Q(2,-5),