八年級(jí)上冊(cè)數(shù)學(xué)畫軸對(duì)稱圖形公開課課件

第十三章軸對(duì)稱畫軸對(duì)稱圖形（2）第十三章軸對(duì)稱畫軸對(duì)稱圖形（2）1.探索利用坐標(biāo)來(lái)表示軸對(duì)稱.2.掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).1.探索利用坐標(biāo)來(lái)表示軸對(duì)稱.一、知識(shí)回顧溫故而知新1、.如何畫軸對(duì)稱圖形？2、畫軸對(duì)稱圖形的關(guān)鍵是什么？一、知識(shí)回顧溫故而知新1、.如何畫軸對(duì)稱圖形？1、如二、自研與組研1、如二、自研與組研關(guān)于y軸對(duì)稱的點(diǎn)的坐標(biāo)具有怎樣的關(guān)系？2、如圖，在平面直角坐標(biāo)系中,你能畫出點(diǎn)A關(guān)于x軸的對(duì)稱點(diǎn)嗎?點(diǎn)P(-5,6)與點(diǎn)Q關(guān)于x軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__________.掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).（1）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線x=1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（2）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線x=-1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（3）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線y=1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（4）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線y=-1對(duì)稱點(diǎn)的坐標(biāo)是多少?掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).點(diǎn)M(a,-6)與點(diǎn)N(-2,b)關(guān)于y軸對(duì)稱，則a=_____,點(diǎn)P(-3,2)與點(diǎn)Q關(guān)于y軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__________.你能說(shuō)出點(diǎn)A與點(diǎn)A′坐標(biāo)的關(guān)系嗎？b=_____.2、如圖，在平面直角坐標(biāo)系中,你能畫出點(diǎn)A關(guān)于x軸的對(duì)稱點(diǎn)嗎?1、在平面直角坐標(biāo)系中畫出下列各點(diǎn)關(guān)于x軸的對(duì)稱點(diǎn).通過(guò)本課時(shí)的學(xué)習(xí)，需要我們掌握：通過(guò)本課時(shí)的學(xué)習(xí)，需要我們掌握：若點(diǎn)P與點(diǎn)P′關(guān)于x軸對(duì)稱，則a=_____,b=_______.1、已知點(diǎn)A和一條直線MN，你能畫出這個(gè)點(diǎn)關(guān)于已知直線MN的對(duì)稱點(diǎn)嗎?關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).關(guān)于y軸對(duì)稱的點(diǎn)的橫坐標(biāo)互為相反數(shù),縱坐標(biāo)相等.如圖，你能在平面直角坐標(biāo)系中畫出點(diǎn)A關(guān)于y軸的對(duì)稱點(diǎn)嗎?1、已知點(diǎn)A和一條直線MN，你能畫出這個(gè)點(diǎn)關(guān)于已知直線MN的對(duì)稱點(diǎn)嗎?AA′MN∴A′就是點(diǎn)A關(guān)于直線MN的對(duì)稱點(diǎn).O然后延長(zhǎng)AO至OA′,使AO=OA′.過(guò)點(diǎn)A作AO⊥MN于O,探究一關(guān)于y軸對(duì)稱的點(diǎn)的坐標(biāo)具有怎樣的關(guān)系？1、已知點(diǎn)A和一條直線你能說(shuō)出點(diǎn)A與點(diǎn)A′坐標(biāo)的關(guān)系嗎？3、已知△ABC的三個(gè)頂點(diǎn)的坐標(biāo)分別為A(-3，5),B(-4，1),點(diǎn)P(-5,6)與點(diǎn)Q關(guān)于x軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__________.點(diǎn)P(-5,6)與點(diǎn)Q關(guān)于x軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__________.掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).2、在平面直角坐標(biāo)系中畫出下列各點(diǎn)關(guān)于y軸的對(duì)稱點(diǎn).若點(diǎn)P與點(diǎn)P′關(guān)于x軸對(duì)稱，則a=_____,b=_______.1、在平面直角坐標(biāo)系中畫出下列各點(diǎn)關(guān)于x軸的對(duì)稱點(diǎn).C(-1，3)，作出△ABC關(guān)于y軸對(duì)稱的圖形.掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.點(diǎn)P(-3,2)與點(diǎn)Q關(guān)于y軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__________.1、已知點(diǎn)A和一條直線MN，你能畫出這個(gè)點(diǎn)關(guān)于已知直線MN的對(duì)稱點(diǎn)嗎?關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.點(diǎn)（x,y）關(guān)于y軸對(duì)稱的點(diǎn)的坐標(biāo)為________.如圖，你能在平面直角坐標(biāo)系中畫出點(diǎn)A關(guān)于y軸的對(duì)稱點(diǎn)嗎?探索利用坐標(biāo)來(lái)表示軸對(duì)稱.1、在平面直角坐標(biāo)系中畫出下列各點(diǎn)關(guān)于x軸的對(duì)稱點(diǎn).·31425-2-4-1-3O12345-4-3-2-1A(2,3)你能說(shuō)出點(diǎn)A與點(diǎn)A′坐標(biāo)的關(guān)系嗎？2、如圖，在平面直角坐標(biāo)系中,你能畫出點(diǎn)A關(guān)于x軸的對(duì)稱點(diǎn)嗎?yx探究二你能說(shuō)出點(diǎn)A與點(diǎn)A′坐標(biāo)的關(guān)系嗎？·31425-2-4-1-·31425-2-4-1-312345-4-3-2-1A(2,3)·A′(2,-3)點(diǎn)A與點(diǎn)A′橫坐標(biāo)相同，縱坐標(biāo)互為相反數(shù).xyO·31425-2-4-1-312345-4-3-2-1A(·31425-2-4-1-312345-4-3-2-1A(2,3)·A′(-2,3)你能說(shuō)出點(diǎn)A與點(diǎn)A′坐標(biāo)的關(guān)系嗎？如圖，你能在平面直角坐標(biāo)系中畫出點(diǎn)A關(guān)于y軸的對(duì)稱點(diǎn)嗎?yxO探究三·31425-2-4-1-312345-4-3-2-1A(31425-2-4-1-312345-4-3-2-1B(-4,2)··C(3,-4)關(guān)于x軸對(duì)稱的點(diǎn)的坐標(biāo)具有怎樣的關(guān)系？1、在平面直角坐標(biāo)系中畫出下列各點(diǎn)關(guān)于x軸的對(duì)稱點(diǎn).yxO三、走進(jìn)展研展示你的風(fēng)采31425-2-4-1-312345-4-3-2-1B(-點(diǎn)M(a,-6)與點(diǎn)N(-2,b)關(guān)于y軸對(duì)稱，則a=_____,掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).若點(diǎn)P與點(diǎn)P′關(guān)于x軸對(duì)稱，則a=_____,b=_______.b=_____.2、如圖，在平面直角坐標(biāo)系中,你能畫出點(diǎn)A關(guān)于x軸的對(duì)稱點(diǎn)嗎?探索利用坐標(biāo)來(lái)表示軸對(duì)稱.關(guān)于x軸對(duì)稱的點(diǎn)的坐標(biāo)具有怎樣的關(guān)系？關(guān)于y軸對(duì)稱的點(diǎn)的坐標(biāo)具有怎樣的關(guān)系？你能說(shuō)出點(diǎn)A與點(diǎn)A′坐標(biāo)的關(guān)系嗎？關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.（1）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線x=1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（2）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線x=-1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（3）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線y=1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（4）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線y=-1對(duì)稱點(diǎn)的坐標(biāo)是多少?通過(guò)本課時(shí)的學(xué)習(xí)，需要我們掌握：然后延長(zhǎng)AO至OA′,使AO=OA′.若點(diǎn)P與點(diǎn)P′關(guān)于y軸對(duì)稱，則a=_____,b=_______.如圖，你能在平面直角坐標(biāo)系中畫出點(diǎn)A關(guān)于y軸的對(duì)稱點(diǎn)嗎?如圖，你能在平面直角坐標(biāo)系中畫出點(diǎn)A關(guān)于y軸的對(duì)稱點(diǎn)嗎?掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).7、如圖,分別作出點(diǎn)P,M,N關(guān)于直線x=1的對(duì)稱點(diǎn),你能發(fā)現(xiàn)它們坐標(biāo)之間分別有什么關(guān)系嗎?B′(-4,-2)關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.31425-2-4-1-312345-4-3-2-1B(-4,2)··C(3,-4)·B′(-4,-2)·C′(3,4)關(guān)于x軸對(duì)稱的點(diǎn)的橫坐標(biāo)相同，縱坐標(biāo)互為相反數(shù).yxO歸納一點(diǎn)M(a,-6)與點(diǎn)N(-2,b)關(guān)于y軸對(duì)稱，則a=_點(diǎn)M(a,-6)與點(diǎn)N(-2,b)關(guān)于y軸對(duì)稱，則a=_____,1、已知點(diǎn)A和一條直線MN，你能畫出這個(gè)點(diǎn)關(guān)于已知直線MN的對(duì)稱點(diǎn)嗎?掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).然后延長(zhǎng)AO至OA′,使AO=OA′.依次連接A′B′,B′C′,關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.如圖，你能在平面直角坐標(biāo)系中畫出點(diǎn)A關(guān)于y軸的對(duì)稱點(diǎn)嗎?1、在平面直角坐標(biāo)系中畫出下列各點(diǎn)關(guān)于x軸的對(duì)稱點(diǎn).若點(diǎn)P與點(diǎn)P′關(guān)于x軸對(duì)稱，則a=_____,b=_______.3、已知△ABC的三個(gè)頂點(diǎn)的坐標(biāo)分別為A(-3，5),B(-4，1),1、已知點(diǎn)A和一條直線MN，你能畫出這個(gè)點(diǎn)關(guān)于已知直線MN的對(duì)稱點(diǎn)嗎?（1）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線x=1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（2）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線x=-1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（3）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線y=1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（4）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線y=-1對(duì)稱點(diǎn)的坐標(biāo)是多少?若點(diǎn)P與點(diǎn)P′關(guān)于x軸對(duì)稱，則a=_____,b=_______.你能說(shuō)出點(diǎn)A與點(diǎn)A′坐標(biāo)的關(guān)系嗎？1、已知點(diǎn)A和一條直線MN，你能畫出這個(gè)點(diǎn)關(guān)于已知直線MN的對(duì)稱點(diǎn)嗎?通過(guò)本課時(shí)的學(xué)習(xí)，需要我們掌握：掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).3、已知△ABC的三個(gè)頂點(diǎn)的坐標(biāo)分別為A(-3，5),B(-4，1),關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.31425-2-4-1-312345-4-3-2-1B(-4,2)··C(3,-4)·B′(4,2)·C′(-3,-4)關(guān)于y軸對(duì)稱的點(diǎn)的坐標(biāo)具有怎樣的關(guān)系？2、在平面直角坐標(biāo)系中畫出下列各點(diǎn)關(guān)于y軸的對(duì)稱點(diǎn).yxO展示你的風(fēng)采關(guān)于y軸對(duì)稱的點(diǎn)的橫坐標(biāo)互為相反數(shù),縱坐標(biāo)相等.點(diǎn)M(a,-6)與點(diǎn)N(-2,b)關(guān)于y軸對(duì)稱，則a=_點(diǎn)（x,y）關(guān)于x軸對(duì)稱的點(diǎn)的坐標(biāo)為________.點(diǎn)（x,y）關(guān)于y軸對(duì)稱的點(diǎn)的坐標(biāo)為________.(x,－y)(－x,y)歸納二點(diǎn)（x,y）關(guān)于x軸對(duì)稱的點(diǎn)的坐標(biāo)為________.(x【解析】點(diǎn)A(-3,5),B(-4,1),C(-1,3)，關(guān)于y軸對(duì)稱點(diǎn)的坐標(biāo)分別為A′(3,5),B′(4,1),C′(1,3).依次連接A′B′,B′C′,C′A′,就得到△ABC關(guān)于y軸對(duì)稱的圖形，即△A′B′C′.····A31425-2-4-1-3O12345-4-3-2-1·CBB′A′C′3、已知△ABC的三個(gè)頂點(diǎn)的坐標(biāo)分別為A(-3，5),B(-4，1),C(-1，3)，作出△ABC關(guān)于y軸對(duì)稱的圖形.yx·展示你的風(fēng)采【解析】點(diǎn)A(-3,5),····A31425-2-4-1-1.點(diǎn)P(-5,6)與點(diǎn)Q關(guān)于x軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__________.2.點(diǎn)M(a,-5)與點(diǎn)N(-2,b)關(guān)于x軸對(duì)稱，則a=_____,b=_____.(-5,-6)-25四、走進(jìn)升研看看誰(shuí)最棒？1.點(diǎn)P(-5,6)與點(diǎn)Q關(guān)于x軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__3.點(diǎn)P(-3,2)與點(diǎn)Q關(guān)于y軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__________.4.點(diǎn)M(a,-6)與點(diǎn)N(-2,b)關(guān)于y軸對(duì)稱，則a=_____,b=_____.(3,2)2-6看看誰(shuí)最棒？3.點(diǎn)P(-3,2)與點(diǎn)Q關(guān)于y軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__5、完成下表:已知點(diǎn)(3,-3)(-1,2)(-8,-5)(0,-1)(4,0)關(guān)于x軸的對(duì)稱點(diǎn)關(guān)于y軸的對(duì)稱點(diǎn)(-3,-3)(3,3)(-1,-2)(1,2)(8,-5)(-8,5)(0,-1)(0,1)(-4,0)（4，0）6、已知點(diǎn)P(2a+b,-3a)與點(diǎn)P′(8,b+2).若點(diǎn)P與點(diǎn)P′關(guān)于x軸對(duì)稱，則a=_____,b=_______.若點(diǎn)P與點(diǎn)P′關(guān)于y軸對(duì)稱，則a=_____,b=_______.246-20看看誰(shuí)最棒？5、完成下表:已知點(diǎn)(3,-3)(-1,2)(-8,-5)(31425-2-4-1-3012345-4-3-2-1x=1·····P(-2,3)M(-1,1)N′(5,-2)N(-3,-2)M′(3,1)P′(4,3)7、如圖,分別作出點(diǎn)P,M,N關(guān)于直線x=1的對(duì)稱點(diǎn),你能發(fā)現(xiàn)它們坐標(biāo)之間分別有什么關(guān)系嗎?·yx看看誰(shuí)最棒？31425-2-4-1-3012345-4-3-2-1x=1（1）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線x=1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（2）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線x=-1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（3）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線y=1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（4）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線y=-1對(duì)稱點(diǎn)的坐標(biāo)是多少?(-x+2,y)(-x-2,y)(x,-y+2)(x,-y-2)規(guī)律（1）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線x=1對(duì)稱點(diǎn)1.關(guān)于x軸對(duì)稱的點(diǎn)橫坐標(biāo)相等，縱坐標(biāo)互為相反數(shù).關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.2.在平面直角坐標(biāo)系中畫一個(gè)圖形關(guān)于x軸或y軸的對(duì)稱圖形：先求出已知圖形中的一些特殊點(diǎn)(如多邊形的頂點(diǎn))的對(duì)應(yīng)點(diǎn)的坐標(biāo),描出并連接這些點(diǎn),就可以得到這個(gè)圖形的軸對(duì)稱圖形.

通過(guò)本課時(shí)的學(xué)習(xí)，需要我們掌握：本節(jié)課你有哪些收獲？1.關(guān)于x軸對(duì)稱的點(diǎn)橫坐標(biāo)相等，縱坐標(biāo)互為相反數(shù).關(guān)于y軸對(duì)技巧:對(duì)于這類問(wèn)題,只要先求出已知圖形中的一些特殊點(diǎn)(如多邊形的頂點(diǎn))的對(duì)應(yīng)點(diǎn)的坐標(biāo),描出并連接這些點(diǎn),就可以得到這個(gè)圖形的軸對(duì)稱圖形.特別提醒技巧:對(duì)于這類問(wèn)題,只要先求出已知圖形中的一些特殊點(diǎn)(如多邊第十三章軸對(duì)稱畫軸對(duì)稱圖形（2）第十三章軸對(duì)稱畫軸對(duì)稱圖形（2）1.探索利用坐標(biāo)來(lái)表示軸對(duì)稱.2.掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).1.探索利用坐標(biāo)來(lái)表示軸對(duì)稱.一、知識(shí)回顧溫故而知新1、.如何畫軸對(duì)稱圖形？2、畫軸對(duì)稱圖形的關(guān)鍵是什么？一、知識(shí)回顧溫故而知新1、.如何畫軸對(duì)稱圖形？1、如二、自研與組研1、如二、自研與組研關(guān)于y軸對(duì)稱的點(diǎn)的坐標(biāo)具有怎樣的關(guān)系？2、如圖，在平面直角坐標(biāo)系中,你能畫出點(diǎn)A關(guān)于x軸的對(duì)稱點(diǎn)嗎?點(diǎn)P(-5,6)與點(diǎn)Q關(guān)于x軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__________.掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).（1）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線x=1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（2）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線x=-1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（3）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線y=1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（4）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線y=-1對(duì)稱點(diǎn)的坐標(biāo)是多少?掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).點(diǎn)M(a,-6)與點(diǎn)N(-2,b)關(guān)于y軸對(duì)稱，則a=_____,點(diǎn)P(-3,2)與點(diǎn)Q關(guān)于y軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__________.你能說(shuō)出點(diǎn)A與點(diǎn)A′坐標(biāo)的關(guān)系嗎？b=_____.2、如圖，在平面直角坐標(biāo)系中,你能畫出點(diǎn)A關(guān)于x軸的對(duì)稱點(diǎn)嗎?1、在平面直角坐標(biāo)系中畫出下列各點(diǎn)關(guān)于x軸的對(duì)稱點(diǎn).通過(guò)本課時(shí)的學(xué)習(xí)，需要我們掌握：通過(guò)本課時(shí)的學(xué)習(xí)，需要我們掌握：若點(diǎn)P與點(diǎn)P′關(guān)于x軸對(duì)稱，則a=_____,b=_______.1、已知點(diǎn)A和一條直線MN，你能畫出這個(gè)點(diǎn)關(guān)于已知直線MN的對(duì)稱點(diǎn)嗎?關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).關(guān)于y軸對(duì)稱的點(diǎn)的橫坐標(biāo)互為相反數(shù),縱坐標(biāo)相等.如圖，你能在平面直角坐標(biāo)系中畫出點(diǎn)A關(guān)于y軸的對(duì)稱點(diǎn)嗎?1、已知點(diǎn)A和一條直線MN，你能畫出這個(gè)點(diǎn)關(guān)于已知直線MN的對(duì)稱點(diǎn)嗎?AA′MN∴A′就是點(diǎn)A關(guān)于直線MN的對(duì)稱點(diǎn).O然后延長(zhǎng)AO至OA′,使AO=OA′.過(guò)點(diǎn)A作AO⊥MN于O,探究一關(guān)于y軸對(duì)稱的點(diǎn)的坐標(biāo)具有怎樣的關(guān)系？1、已知點(diǎn)A和一條直線你能說(shuō)出點(diǎn)A與點(diǎn)A′坐標(biāo)的關(guān)系嗎？3、已知△ABC的三個(gè)頂點(diǎn)的坐標(biāo)分別為A(-3，5),B(-4，1),點(diǎn)P(-5,6)與點(diǎn)Q關(guān)于x軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__________.點(diǎn)P(-5,6)與點(diǎn)Q關(guān)于x軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__________.掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).2、在平面直角坐標(biāo)系中畫出下列各點(diǎn)關(guān)于y軸的對(duì)稱點(diǎn).若點(diǎn)P與點(diǎn)P′關(guān)于x軸對(duì)稱，則a=_____,b=_______.1、在平面直角坐標(biāo)系中畫出下列各點(diǎn)關(guān)于x軸的對(duì)稱點(diǎn).C(-1，3)，作出△ABC關(guān)于y軸對(duì)稱的圖形.掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.點(diǎn)P(-3,2)與點(diǎn)Q關(guān)于y軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__________.1、已知點(diǎn)A和一條直線MN，你能畫出這個(gè)點(diǎn)關(guān)于已知直線MN的對(duì)稱點(diǎn)嗎?關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.點(diǎn)（x,y）關(guān)于y軸對(duì)稱的點(diǎn)的坐標(biāo)為________.如圖，你能在平面直角坐標(biāo)系中畫出點(diǎn)A關(guān)于y軸的對(duì)稱點(diǎn)嗎?探索利用坐標(biāo)來(lái)表示軸對(duì)稱.1、在平面直角坐標(biāo)系中畫出下列各點(diǎn)關(guān)于x軸的對(duì)稱點(diǎn).·31425-2-4-1-3O12345-4-3-2-1A(2,3)你能說(shuō)出點(diǎn)A與點(diǎn)A′坐標(biāo)的關(guān)系嗎？2、如圖，在平面直角坐標(biāo)系中,你能畫出點(diǎn)A關(guān)于x軸的對(duì)稱點(diǎn)嗎?yx探究二你能說(shuō)出點(diǎn)A與點(diǎn)A′坐標(biāo)的關(guān)系嗎？·31425-2-4-1-·31425-2-4-1-312345-4-3-2-1A(2,3)·A′(2,-3)點(diǎn)A與點(diǎn)A′橫坐標(biāo)相同，縱坐標(biāo)互為相反數(shù).xyO·31425-2-4-1-312345-4-3-2-1A(·31425-2-4-1-312345-4-3-2-1A(2,3)·A′(-2,3)你能說(shuō)出點(diǎn)A與點(diǎn)A′坐標(biāo)的關(guān)系嗎？如圖，你能在平面直角坐標(biāo)系中畫出點(diǎn)A關(guān)于y軸的對(duì)稱點(diǎn)嗎?yxO探究三·31425-2-4-1-312345-4-3-2-1A(31425-2-4-1-312345-4-3-2-1B(-4,2)··C(3,-4)關(guān)于x軸對(duì)稱的點(diǎn)的坐標(biāo)具有怎樣的關(guān)系？1、在平面直角坐標(biāo)系中畫出下列各點(diǎn)關(guān)于x軸的對(duì)稱點(diǎn).yxO三、走進(jìn)展研展示你的風(fēng)采31425-2-4-1-312345-4-3-2-1B(-點(diǎn)M(a,-6)與點(diǎn)N(-2,b)關(guān)于y軸對(duì)稱，則a=_____,掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).若點(diǎn)P與點(diǎn)P′關(guān)于x軸對(duì)稱，則a=_____,b=_______.b=_____.2、如圖，在平面直角坐標(biāo)系中,你能畫出點(diǎn)A關(guān)于x軸的對(duì)稱點(diǎn)嗎?探索利用坐標(biāo)來(lái)表示軸對(duì)稱.關(guān)于x軸對(duì)稱的點(diǎn)的坐標(biāo)具有怎樣的關(guān)系？關(guān)于y軸對(duì)稱的點(diǎn)的坐標(biāo)具有怎樣的關(guān)系？你能說(shuō)出點(diǎn)A與點(diǎn)A′坐標(biāo)的關(guān)系嗎？關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.（1）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線x=1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（2）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線x=-1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（3）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線y=1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（4）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線y=-1對(duì)稱點(diǎn)的坐標(biāo)是多少?通過(guò)本課時(shí)的學(xué)習(xí)，需要我們掌握：然后延長(zhǎng)AO至OA′,使AO=OA′.若點(diǎn)P與點(diǎn)P′關(guān)于y軸對(duì)稱，則a=_____,b=_______.如圖，你能在平面直角坐標(biāo)系中畫出點(diǎn)A關(guān)于y軸的對(duì)稱點(diǎn)嗎?如圖，你能在平面直角坐標(biāo)系中畫出點(diǎn)A關(guān)于y軸的對(duì)稱點(diǎn)嗎?掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).7、如圖,分別作出點(diǎn)P,M,N關(guān)于直線x=1的對(duì)稱點(diǎn),你能發(fā)現(xiàn)它們坐標(biāo)之間分別有什么關(guān)系嗎?B′(-4,-2)關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.31425-2-4-1-312345-4-3-2-1B(-4,2)··C(3,-4)·B′(-4,-2)·C′(3,4)關(guān)于x軸對(duì)稱的點(diǎn)的橫坐標(biāo)相同，縱坐標(biāo)互為相反數(shù).yxO歸納一點(diǎn)M(a,-6)與點(diǎn)N(-2,b)關(guān)于y軸對(duì)稱，則a=_點(diǎn)M(a,-6)與點(diǎn)N(-2,b)關(guān)于y軸對(duì)稱，則a=_____,1、已知點(diǎn)A和一條直線MN，你能畫出這個(gè)點(diǎn)關(guān)于已知直線MN的對(duì)稱點(diǎn)嗎?掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).然后延長(zhǎng)AO至OA′,使AO=OA′.依次連接A′B′,B′C′,關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.如圖，你能在平面直角坐標(biāo)系中畫出點(diǎn)A關(guān)于y軸的對(duì)稱點(diǎn)嗎?1、在平面直角坐標(biāo)系中畫出下列各點(diǎn)關(guān)于x軸的對(duì)稱點(diǎn).若點(diǎn)P與點(diǎn)P′關(guān)于x軸對(duì)稱，則a=_____,b=_______.3、已知△ABC的三個(gè)頂點(diǎn)的坐標(biāo)分別為A(-3，5),B(-4，1),1、已知點(diǎn)A和一條直線MN，你能畫出這個(gè)點(diǎn)關(guān)于已知直線MN的對(duì)稱點(diǎn)嗎?（1）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線x=1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（2）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線x=-1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（3）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線y=1對(duì)稱點(diǎn)的坐標(biāo)是多少?

（4）、在平面直角坐標(biāo)系中,點(diǎn)(x,y)關(guān)于直線y=-1對(duì)稱點(diǎn)的坐標(biāo)是多少?若點(diǎn)P與點(diǎn)P′關(guān)于x軸對(duì)稱，則a=_____,b=_______.你能說(shuō)出點(diǎn)A與點(diǎn)A′坐標(biāo)的關(guān)系嗎？1、已知點(diǎn)A和一條直線MN，你能畫出這個(gè)點(diǎn)關(guān)于已知直線MN的對(duì)稱點(diǎn)嗎?通過(guò)本課時(shí)的學(xué)習(xí)，需要我們掌握：掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).掌握關(guān)于x軸、y軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn).3、已知△ABC的三個(gè)頂點(diǎn)的坐標(biāo)分別為A(-3，5),B(-4，1),關(guān)于y軸對(duì)稱的點(diǎn)橫坐標(biāo)互為相反數(shù)，縱坐標(biāo)相等.31425-2-4-1-312345-4-3-2-1B(-4,2)··C(3,-4)·B′(4,2)·C′(-3,-4)關(guān)于y軸對(duì)稱的點(diǎn)的坐標(biāo)具有怎樣的關(guān)系？2、在平面直角坐標(biāo)系中畫出下列各點(diǎn)關(guān)于y軸的對(duì)稱點(diǎn).yxO展示你的風(fēng)采關(guān)于y軸對(duì)稱的點(diǎn)的橫坐標(biāo)互為相反數(shù),縱坐標(biāo)相等.點(diǎn)M(a,-6)與點(diǎn)N(-2,b)關(guān)于y軸對(duì)稱，則a=_點(diǎn)（x,y）關(guān)于x軸對(duì)稱的點(diǎn)的坐標(biāo)為________.點(diǎn)（x,y）關(guān)于y軸對(duì)稱的點(diǎn)的坐標(biāo)為________.(x,－y)(－x,y)歸納二點(diǎn)（x,y）關(guān)于x軸對(duì)稱的點(diǎn)的坐標(biāo)為________.(x【解析】點(diǎn)A(-3,5),B(-4,1),C(-1,3)，關(guān)于y軸對(duì)稱點(diǎn)的坐標(biāo)分別為A′(3,5),B′(4,1),C′(1,3).依次連接A′B′,B′C′,C′A′,就得到△ABC關(guān)于y軸對(duì)稱的圖形，即△A′B′C′.····A31425-2-4-1-3O12345-4-3-2-1·CBB′A′C′3、已知△ABC的三個(gè)頂點(diǎn)的坐標(biāo)分別為A(-3，5),B(-4，1),C(-1，3)，作出△ABC關(guān)于y軸對(duì)稱的圖形.yx·展示你的風(fēng)采【解析】點(diǎn)A(-3,5),····A31425-2-4-1-1.點(diǎn)P(-5,6)與點(diǎn)Q關(guān)于x軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__________.2.點(diǎn)M(a,-5)與點(diǎn)N(-2,b)關(guān)于x軸對(duì)稱，則a=_____,b=_____.(-5,-6)-25四、走進(jìn)升研看看誰(shuí)最棒？1.點(diǎn)P(-5,6)與點(diǎn)Q關(guān)于x軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__3.點(diǎn)P(-3,2)與點(diǎn)Q關(guān)于y軸對(duì)稱，則點(diǎn)Q的坐標(biāo)為__________.4.點(diǎn)M(a,-6)與點(diǎn)N(-2,b)關(guān)于y軸對(duì)稱，則a=_____,b=_____.(3,2)2-6看看誰(shuí)最棒？3.點(diǎn)P(-3