《湘教版八年級(jí)下冊(cè)數(shù)學(xué)課件 第3章 3.3.1 軸對(duì)稱(chēng)的坐標(biāo)表示》由會(huì)員分享,可在線閱讀,更多相關(guān)《湘教版八年級(jí)下冊(cè)數(shù)學(xué)課件 第3章 3.3.1 軸對(duì)稱(chēng)的坐標(biāo)表示(25頁(yè)珍藏版)》請(qǐng)?jiān)谘b配圖網(wǎng)上搜索。
1、 湘教版湘教版 八年級(jí)下八年級(jí)下第第1課時(shí)軸對(duì)稱(chēng)的坐標(biāo)表示課時(shí)軸對(duì)稱(chēng)的坐標(biāo)表示第3章圖形與坐標(biāo)習(xí)題鏈接習(xí)題鏈接提示:點(diǎn)擊 進(jìn)入習(xí)題答案顯示答案顯示6789ABBB10C1234ABA(4,1);(4,3)5(2,1)11121314C4(3,3)見(jiàn)習(xí)題見(jiàn)習(xí)題15見(jiàn)習(xí)題見(jiàn)習(xí)題16見(jiàn)習(xí)題見(jiàn)習(xí)題12(a,b);相反數(shù)相反數(shù)(a,b);相反數(shù)相反數(shù)新知筆記17 見(jiàn)習(xí)題見(jiàn)習(xí)題新知筆記新知筆記1在平面直角坐標(biāo)系中,點(diǎn)在平面直角坐標(biāo)系中,點(diǎn)(a,b)關(guān)于關(guān)于x軸的對(duì)稱(chēng)點(diǎn)的坐標(biāo)軸的對(duì)稱(chēng)點(diǎn)的坐標(biāo)為為_(kāi)(橫坐標(biāo)不變,縱坐標(biāo)互為橫坐標(biāo)不變,縱坐標(biāo)互為_(kāi))(a,b)相反數(shù)相反數(shù)新知筆記新知筆記2在平面直角坐標(biāo)系中,點(diǎn)
2、在平面直角坐標(biāo)系中,點(diǎn)(a,b)關(guān)于關(guān)于y軸的對(duì)稱(chēng)點(diǎn)的坐標(biāo)軸的對(duì)稱(chēng)點(diǎn)的坐標(biāo)為為_(kāi)(橫坐標(biāo)互為橫坐標(biāo)互為_(kāi),縱坐標(biāo)不變,縱坐標(biāo)不變)(a,b)相反數(shù)相反數(shù)基礎(chǔ)鞏固練基礎(chǔ)鞏固練1【中考中考甘孜州甘孜州】在平面直角坐標(biāo)系中,點(diǎn)在平面直角坐標(biāo)系中,點(diǎn)(2,1)關(guān)于關(guān)于x軸對(duì)稱(chēng)的點(diǎn)是軸對(duì)稱(chēng)的點(diǎn)是()A(2,1)B(1,2)C(1,2)D(2,1)A基礎(chǔ)鞏固練基礎(chǔ)鞏固練2【中考中考濱州濱州】點(diǎn)點(diǎn)P在平面直角坐標(biāo)系中,位于在平面直角坐標(biāo)系中,位于x軸上方,距軸上方,距離離x軸軸3個(gè)單位長(zhǎng)度,距離個(gè)單位長(zhǎng)度,距離y軸軸4個(gè)單位長(zhǎng)度,則點(diǎn)個(gè)單位長(zhǎng)度,則點(diǎn)P關(guān)于關(guān)于x軸軸對(duì)稱(chēng)的點(diǎn)的坐標(biāo)是對(duì)稱(chēng)的點(diǎn)的坐標(biāo)是()A(3
3、,4)或或(3,4)B(4,3)或或(4,3)C(3,4)或或(3,4)D(4,3)或或(4,3)B【點(diǎn)撥點(diǎn)撥】點(diǎn)點(diǎn)P在平面直角坐標(biāo)系中,位于在平面直角坐標(biāo)系中,位于x軸上方,距離軸上方,距離x軸軸3個(gè)個(gè)單位長(zhǎng)度,距離單位長(zhǎng)度,距離y軸軸4個(gè)單位長(zhǎng)度,個(gè)單位長(zhǎng)度,點(diǎn)點(diǎn)P的坐標(biāo)是的坐標(biāo)是(4,3)或或(4,3),則點(diǎn),則點(diǎn)P關(guān)于關(guān)于x軸對(duì)稱(chēng)的點(diǎn)的坐標(biāo)是軸對(duì)稱(chēng)的點(diǎn)的坐標(biāo)是(4,3)或或(4,3)基礎(chǔ)鞏固練基礎(chǔ)鞏固練3若點(diǎn)若點(diǎn)A(m,2)與點(diǎn)與點(diǎn)B(3,n)關(guān)于關(guān)于x軸對(duì)稱(chēng),則軸對(duì)稱(chēng),則mn的值的值是是()A1 B2 C2 D5A基礎(chǔ)鞏固練基礎(chǔ)鞏固練4如圖,在矩形如圖,在矩形ABCD中,點(diǎn)中,點(diǎn)A(
4、4,1),B(0,1),C(0,3),則點(diǎn)則點(diǎn)A關(guān)于關(guān)于x軸的對(duì)稱(chēng)點(diǎn)軸的對(duì)稱(chēng)點(diǎn)A的坐標(biāo)是的坐標(biāo)是_;點(diǎn);點(diǎn)D的坐標(biāo)是的坐標(biāo)是_(4,1)(4,3)基礎(chǔ)鞏固練基礎(chǔ)鞏固練5已知點(diǎn)已知點(diǎn)P(x,y)的坐標(biāo)滿足等式的坐標(biāo)滿足等式(x2)2|y1|0,且點(diǎn),且點(diǎn)P與與點(diǎn)點(diǎn)P關(guān)于關(guān)于x軸對(duì)稱(chēng),則點(diǎn)軸對(duì)稱(chēng),則點(diǎn)P的坐標(biāo)為的坐標(biāo)為_(kāi)(2,1)【點(diǎn)撥點(diǎn)撥】(x2)2|y1|0,x20,y10.解得解得x2,y1,P點(diǎn)坐標(biāo)為點(diǎn)坐標(biāo)為(2,1),點(diǎn)點(diǎn)P關(guān)于關(guān)于x軸的對(duì)稱(chēng)點(diǎn)軸的對(duì)稱(chēng)點(diǎn)P的坐標(biāo)為的坐標(biāo)為(2,1)基礎(chǔ)鞏固練基礎(chǔ)鞏固練6【中考中考湘潭湘潭】如圖,點(diǎn)如圖,點(diǎn)A的坐標(biāo)為的坐標(biāo)為(1,2),則點(diǎn),則點(diǎn)A關(guān)于關(guān)于
5、y軸對(duì)稱(chēng)的點(diǎn)的坐標(biāo)為軸對(duì)稱(chēng)的點(diǎn)的坐標(biāo)為()A(1,2)B(1,2)C(1,2)D(2,1)A基礎(chǔ)鞏固練基礎(chǔ)鞏固練7【中考中考杭州杭州】在平面直角坐標(biāo)系中,點(diǎn)在平面直角坐標(biāo)系中,點(diǎn)A(m,2)與點(diǎn)與點(diǎn)B(3,n)關(guān)于關(guān)于y軸對(duì)稱(chēng),則軸對(duì)稱(chēng),則()Am3,n2 Bm3,n2Cm2,n3 Dm2,n3B【點(diǎn)撥點(diǎn)撥】A,B關(guān)于關(guān)于y軸對(duì)稱(chēng),則兩點(diǎn)橫坐標(biāo)互為軸對(duì)稱(chēng),則兩點(diǎn)橫坐標(biāo)互為相反數(shù),縱坐標(biāo)相同,故選相反數(shù),縱坐標(biāo)相同,故選B.基礎(chǔ)鞏固練基礎(chǔ)鞏固練8已知點(diǎn)已知點(diǎn)P的坐標(biāo)為的坐標(biāo)為(a,b),那么點(diǎn),那么點(diǎn)P關(guān)于關(guān)于y軸對(duì)稱(chēng)的點(diǎn)軸對(duì)稱(chēng)的點(diǎn)的坐標(biāo)為的坐標(biāo)為()A(a,b)B(a,b)C(a,b)D(a,
6、b)B基礎(chǔ)鞏固練基礎(chǔ)鞏固練9如圖,如圖,OAB和和OCB關(guān)于關(guān)于x軸對(duì)稱(chēng),軸對(duì)稱(chēng),OCD和和OED關(guān)關(guān)于于y軸對(duì)稱(chēng),若點(diǎn)軸對(duì)稱(chēng),若點(diǎn)E的坐標(biāo)為的坐標(biāo)為(4,6),則點(diǎn),則點(diǎn)A的坐標(biāo)為的坐標(biāo)為()A(6,6)B(4,6)C(6,4)D(4,4)B基礎(chǔ)鞏固練基礎(chǔ)鞏固練10下列圖形中,將圖形上各點(diǎn)的縱坐標(biāo)保持不變,橫坐標(biāo)下列圖形中,將圖形上各點(diǎn)的縱坐標(biāo)保持不變,橫坐標(biāo)分別乘分別乘1后,圖形一定不發(fā)生變化的是后,圖形一定不發(fā)生變化的是()圓心在原點(diǎn)的圓;兩條對(duì)角線的交點(diǎn)在原點(diǎn)的正方圓心在原點(diǎn)的圓;兩條對(duì)角線的交點(diǎn)在原點(diǎn)的正方形;以形;以y軸為對(duì)稱(chēng)軸的等腰三角形;以軸為對(duì)稱(chēng)軸的等腰三角形;以x軸為對(duì)稱(chēng)軸
7、軸為對(duì)稱(chēng)軸的等腰三角形的等腰三角形A BC DC能力提升練能力提升練11【原創(chuàng)題原創(chuàng)題】已知點(diǎn)已知點(diǎn)A的坐標(biāo)為的坐標(biāo)為(2,3),點(diǎn),點(diǎn)A關(guān)于關(guān)于x軸對(duì)稱(chēng)軸對(duì)稱(chēng)的點(diǎn)為的點(diǎn)為A,則,則A關(guān)于關(guān)于y軸對(duì)稱(chēng)的點(diǎn)的坐標(biāo)為軸對(duì)稱(chēng)的點(diǎn)的坐標(biāo)為()A(2,3)B(2,3)C(2,3)D以上都不對(duì)以上都不對(duì)C【點(diǎn)撥點(diǎn)撥】易知與點(diǎn)易知與點(diǎn)A(2,3)關(guān)于關(guān)于x軸對(duì)稱(chēng)的點(diǎn)的坐標(biāo)為軸對(duì)稱(chēng)的點(diǎn)的坐標(biāo)為(2,3),(2,3)關(guān)于關(guān)于y軸對(duì)稱(chēng)的點(diǎn)的坐標(biāo)為軸對(duì)稱(chēng)的點(diǎn)的坐標(biāo)為(2,3)能力提升練能力提升練12【中考中考瀘州瀘州】在平面直角坐標(biāo)系中,點(diǎn)在平面直角坐標(biāo)系中,點(diǎn)M(a,b)與點(diǎn)與點(diǎn)N(3,1)關(guān)于關(guān)于x軸對(duì)稱(chēng),則軸
8、對(duì)稱(chēng),則ab的值是的值是_4【點(diǎn)撥點(diǎn)撥】點(diǎn)點(diǎn)M(a,b)與點(diǎn)與點(diǎn)N(3,1)關(guān)于關(guān)于x軸對(duì)稱(chēng),軸對(duì)稱(chēng),a3,b1,ab4.能力提升練能力提升練13如圖,在平面直角坐標(biāo)系中,如圖,在平面直角坐標(biāo)系中,AOB的頂點(diǎn)的頂點(diǎn)O和和B的坐標(biāo)的坐標(biāo)分別是分別是O(0,0),B(6,0),且,且OAB90,AOAB,則頂點(diǎn)則頂點(diǎn)A關(guān)于關(guān)于x軸對(duì)稱(chēng)的點(diǎn)的坐標(biāo)是軸對(duì)稱(chēng)的點(diǎn)的坐標(biāo)是_(3,3)能力提升練能力提升練14寫(xiě)出如圖所示的寫(xiě)出如圖所示的“小魚(yú)小魚(yú)”上所標(biāo)各點(diǎn)的坐標(biāo)并回答:上所標(biāo)各點(diǎn)的坐標(biāo)并回答:(1)點(diǎn)點(diǎn)B,E的位置有什么特點(diǎn)?的位置有什么特點(diǎn)?解:點(diǎn)解:點(diǎn)A,B,C,D,E的坐標(biāo)分別為的坐標(biāo)分別為(2,
9、0),(0,2),(2,1),(2,1),(0,2)點(diǎn)點(diǎn)B和點(diǎn)和點(diǎn)E關(guān)于關(guān)于x軸對(duì)稱(chēng)軸對(duì)稱(chēng)能力提升練能力提升練(2)從點(diǎn)從點(diǎn)B與點(diǎn)與點(diǎn)E,點(diǎn),點(diǎn)C與點(diǎn)與點(diǎn)D的位置看,它們的坐標(biāo)有什么的位置看,它們的坐標(biāo)有什么特點(diǎn)?特點(diǎn)?解:點(diǎn)解:點(diǎn)B(0,2)與點(diǎn)與點(diǎn)E(0,2),點(diǎn),點(diǎn)C(2,1)與點(diǎn)與點(diǎn)D(2,1),它們的橫坐標(biāo)相同,縱坐標(biāo)互為相反數(shù)它們的橫坐標(biāo)相同,縱坐標(biāo)互為相反數(shù)能力提升練能力提升練15如圖,在平面直角坐標(biāo)系中,已知點(diǎn)如圖,在平面直角坐標(biāo)系中,已知點(diǎn)A(1,5),B(1,0),C(4,3)(1)求求ABC的面積;的面積;能力提升練能力提升練(2)在圖中作出在圖中作出ABC關(guān)于關(guān)于y軸對(duì)
10、稱(chēng)的圖形軸對(duì)稱(chēng)的圖形A1B1C1;(3)寫(xiě)出點(diǎn)寫(xiě)出點(diǎn)A1,B1,C1的坐標(biāo)的坐標(biāo)解:如圖解:如圖A1(1,5),B1(1,0),C1(4,3)能力提升練能力提升練16如圖,解答下列問(wèn)題:如圖,解答下列問(wèn)題:(1)寫(xiě)出寫(xiě)出A,B,C三點(diǎn)的坐標(biāo)三點(diǎn)的坐標(biāo)解:解:A(3,4),B(1,2),C(5,1)能力提升練能力提升練(2)若若ABC各頂點(diǎn)的橫坐標(biāo)不變,縱坐標(biāo)都乘各頂點(diǎn)的橫坐標(biāo)不變,縱坐標(biāo)都乘1,請(qǐng)你在同,請(qǐng)你在同一坐標(biāo)系中描出對(duì)應(yīng)的點(diǎn)一坐標(biāo)系中描出對(duì)應(yīng)的點(diǎn)A,B,C,并依次連接這三個(gè)點(diǎn),并依次連接這三個(gè)點(diǎn),所得的所得的ABC與與ABC有怎樣的位置關(guān)系?有怎樣的位置關(guān)系?(3)求求ABC的面積的
11、面積解:圖略解:圖略ABC與與ABC關(guān)于關(guān)于x軸對(duì)稱(chēng)軸對(duì)稱(chēng)素養(yǎng)核心練素養(yǎng)核心練17平面直角坐標(biāo)系中有一點(diǎn)平面直角坐標(biāo)系中有一點(diǎn)A(1,1),對(duì)點(diǎn),對(duì)點(diǎn)A進(jìn)行如下操作:進(jìn)行如下操作:第一步:作點(diǎn)第一步:作點(diǎn)A關(guān)于關(guān)于x軸的對(duì)稱(chēng)點(diǎn)軸的對(duì)稱(chēng)點(diǎn)A1,延長(zhǎng)線段,延長(zhǎng)線段AA1到點(diǎn)到點(diǎn)A2,使得使得2A1A2AA1;第二步:作點(diǎn)第二步:作點(diǎn)A2關(guān)于關(guān)于y軸的對(duì)稱(chēng)點(diǎn)軸的對(duì)稱(chēng)點(diǎn)A3,延長(zhǎng)線段,延長(zhǎng)線段A2A3到點(diǎn)到點(diǎn)A4,使得使得2A3A4A2A3;第三步:作點(diǎn)第三步:作點(diǎn)A4關(guān)于關(guān)于x軸的對(duì)稱(chēng)點(diǎn)軸的對(duì)稱(chēng)點(diǎn)A5,延長(zhǎng)線段,延長(zhǎng)線段A4A5到點(diǎn)到點(diǎn)A6,使得使得2A5A6A4A5;素養(yǎng)核心練素養(yǎng)核心練(1)點(diǎn)點(diǎn)A2的坐標(biāo)為的坐標(biāo)為_(kāi),點(diǎn),點(diǎn)A2 021的坐標(biāo)為的坐標(biāo)為_(kāi);(2)若點(diǎn)若點(diǎn)An的坐標(biāo)恰好為的坐標(biāo)恰好為(4m,4n)(m,n均為正整數(shù)均為正整數(shù)),請(qǐng)寫(xiě)出,請(qǐng)寫(xiě)出m和和n的關(guān)系式:的關(guān)系式:_(1,2)(2505,2505)mn