文档介绍:将坐标为(0,0),(5,4),(3,0),(5,1),(5,-1),(3,0),(4,-2),(0,0)的点?在直角坐标系中描出以下各点:(x,y)(0,0)(5,4)(3,0)(5,1)(5,-1)(3,0)(4,-2)(0,0)若纵坐标保持不变,横坐标分别加上3,所得各点坐标分别是什么?在平面直角坐标系中依次连接所得各点坐标,并观察所得的鱼与原来的鱼相比有什么变化?表二:(x+3,y)(3,0)(8,4)(6,0)(8,1)(8,-1)(6,0)(7,-2)(3,0)同原图象比较你发现有什么变化?原图形被向右平移3个单位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而成的则坐标变为:(-2,0)(3,4)(1,0)(3,1)(3,-1)(1,0)(2,-2)(-2,0)纵坐标保持不变,将各坐标的横坐标加上-2,图案会变成什么样?yx-1-2原图形被向左平移2个单位猜一猜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+2,则原图型变为什么样?yx猜一猜原图形被纵向(向上)平移2个单位(X,Y)-(X,Y+2)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-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(X,Y)----(X,Y–1)对于上图,若纵坐标保持不变,横坐标分别变成原来的2倍,所得各点坐标分别是什么?(x,y)(0,0)(5,4)(3,0)(5,1)(5,-1)(3,0)(4,-2)(0,0)(2x,y)(0,0)(10,4)(6,0)(10,1)(10,-1)(6,0)(8,-2)(0,0)表一:?原图形被横向拉伸2倍引入探究一探究二议一议想一想纵坐标保持不变,将各坐标的横坐标变成原来的1/2,图形会怎么变?123456780–1–2–3–4–512349105yx原图形被横向压缩1/2–4123456780–1–2–361234578910xy如果横坐标保持不变,纵坐标变成原来的2倍,那么所得图案又会发生什么变化?猜一猜原图形被纵向拉伸2倍(X,Y)----(X,2Y)–4123456780–1–2–361234578910xy如果横坐标保持不变,纵坐标变成原来的½,那么所得图案又会发生什么变化?猜一猜原图形被纵向压缩1/2(X,Y)----(X,1/2Y)