2022年八年級(jí)上冊(cè) 數(shù)學(xué)【推薦】13.2畫軸對(duì)稱圖形-用坐標(biāo)表示軸對(duì)稱（第2課時(shí)）-同步練習(xí)

第2課時(shí)用坐標(biāo)表示軸對(duì)稱要點(diǎn)感知點(diǎn)(x,y)關(guān)于x軸的對(duì)稱的點(diǎn)的坐標(biāo)為______；點(diǎn)(x,y)關(guān)于y軸的對(duì)稱的點(diǎn)的坐標(biāo)為_____.預(yù)習(xí)練習(xí)點(diǎn)P(-2,1)關(guān)于x軸對(duì)稱的點(diǎn)的坐標(biāo)為_____.點(diǎn)P(3,-1)關(guān)于y軸對(duì)稱的點(diǎn)的坐標(biāo)為_____.知識(shí)點(diǎn)1關(guān)于坐標(biāo)軸對(duì)稱的點(diǎn)的坐標(biāo)1.(泰州中考)點(diǎn)A(-2，3)關(guān)于x軸的對(duì)稱點(diǎn)A′的坐標(biāo)為_____.2.已知點(diǎn)P(a,3)，Q(-2,b)關(guān)于x軸對(duì)稱,則a=_____,b=_____.3.點(diǎn)M(-2,1)關(guān)于y軸對(duì)稱的點(diǎn)N的坐標(biāo)是_____,直線MN與y軸的位置關(guān)系是_____.4.分別寫出下列各點(diǎn)關(guān)于x軸和y軸對(duì)稱的點(diǎn)的坐標(biāo)：(2,3),(-2,4),(-3,-3),(2,0),(0,-3).5.已知點(diǎn)A(a+2b,1),B(-2,2a-b).(1)若點(diǎn)A，B關(guān)于x軸對(duì)稱,求a,b的值；(2)若點(diǎn)A，B關(guān)于y軸對(duì)稱,求a+b的值.知識(shí)點(diǎn)2圖形關(guān)于坐標(biāo)軸對(duì)稱6.如圖,陰影部分組成的圖案既是關(guān)于x軸成軸對(duì)稱的圖形又是關(guān)于y軸成軸對(duì)稱的圖形.若點(diǎn)A的坐標(biāo)是(1,3),則點(diǎn)M和點(diǎn)N的坐標(biāo)分別是()A.M(1,-3),N(-1,-3) B.M(-1,-3),N(-1,3) C.M(-1,-3),N(1,-3) D.M(-1,3),N(1,-3)7.已知正方形ABCD在坐標(biāo)軸上的位置如圖所示,x軸、y軸分別是正方形的兩條對(duì)稱軸,若A(2,2),則B點(diǎn)的坐標(biāo)為_____,C點(diǎn)的坐標(biāo)為_____,D點(diǎn)的坐標(biāo)為_____.8.如圖所示,在直角坐標(biāo)系xOy中,A(-1,5),B(-3,0),C(-4,3).(1)在圖中作出△ABC關(guān)于y軸的軸對(duì)稱圖形△A′B′C′；(2)寫出點(diǎn)C關(guān)于y軸的對(duì)稱點(diǎn)C′的坐標(biāo).9.(遂寧中考)將點(diǎn)A(3，2)沿x軸向左平移4個(gè)單位長(zhǎng)度得到點(diǎn)A′，點(diǎn)A′關(guān)于y軸對(duì)稱的點(diǎn)的坐標(biāo)是()A.(-3，2) B.(-1，2) C.(1，2) D.(1，-2)10.在平面直角坐標(biāo)系中,將點(diǎn)A(1,2)的橫坐標(biāo)乘以-1,縱坐標(biāo)不變,得到點(diǎn)A′,則點(diǎn)A與點(diǎn)A′的關(guān)系是()A.關(guān)于x軸對(duì)稱 B.關(guān)于y軸對(duì)稱 C.關(guān)于原點(diǎn)對(duì)稱 D.將點(diǎn)A向x軸負(fù)方向平移了一個(gè)單位得到點(diǎn)A′11.若點(diǎn)M(a-1，b-1)在第三象限，則它關(guān)于x軸軸對(duì)稱的點(diǎn)所在象限是()A.第一象限 B.第二象限 C.第三象限 D.第四象限12.已知點(diǎn)A(a，b)關(guān)于x軸對(duì)稱點(diǎn)的坐標(biāo)是(a，-12)，關(guān)于y軸對(duì)稱點(diǎn)的坐標(biāo)是(５，b)，則Ａ點(diǎn)的坐標(biāo)是_____.13.(遵義中考)已知點(diǎn)P(3，-1)關(guān)于y軸的對(duì)稱點(diǎn)Q的坐標(biāo)是(a+b，1-b)，則ab的值為_____.14.已知P1點(diǎn)關(guān)于x軸的對(duì)稱點(diǎn)P2(3-2a，2a-5)是第三象限內(nèi)的整點(diǎn)(橫、縱坐標(biāo)都為整數(shù)的點(diǎn)，稱為整點(diǎn))，則P1點(diǎn)的坐標(biāo)是_____.15.如圖所示,已知A(-2,-1),B(1,0),C(0,1),請(qǐng)你利用坐標(biāo)軸對(duì)稱的點(diǎn)的坐標(biāo)特點(diǎn),分別作出與△ABC關(guān)于x軸和y軸對(duì)稱的圖形,并寫出相應(yīng)點(diǎn)的坐標(biāo).16.已知點(diǎn)A(-3,2),且點(diǎn)A與點(diǎn)B,點(diǎn)B與點(diǎn)C,點(diǎn)C與點(diǎn)D分別關(guān)于x軸，y軸，x軸對(duì)稱.(1)寫出B，C，D的坐標(biāo)；(2)問四邊形ABCD是什么四邊形？(3)試求四邊形ABCD的面積.挑戰(zhàn)自我17.如圖所示，在平面直角坐標(biāo)系xOy中，A(-1，5)，B(-1，0)，C(-4，3)，直線m為橫坐標(biāo)都為2的點(diǎn)組成的一條直線.(1)作出△ABC關(guān)于直線m對(duì)稱的△A1B1C1(2)直接寫出A1，B1，C1的坐標(biāo)；求出△A1B1C1參考答案課前預(yù)習(xí)要點(diǎn)感知(x,-y)(-x,y)預(yù)習(xí)練習(xí)(-2,-1)(-3,-1)當(dāng)堂訓(xùn)練1.(-2，-3) 2.-2-3 3.(2,1)垂直 4.各點(diǎn)關(guān)于x軸的對(duì)稱的點(diǎn)的坐標(biāo)分別是(2,-3),(-2,-4),(-3,3),(2,0),(0,3)；關(guān)于y軸的對(duì)稱的點(diǎn)的坐標(biāo)分別是(-2,3),(2,4),(3,-3),(-2,0),(0,-3).5.(1)由題意得a+2b=-2,2a-b=-1.解得a=-,b=-.(2)由題意得a+2b=2,2a-b=1.解得a=,b=.∴a+b=. 6.C 7.(2,-2)(-2,-2)(-2,2) 8.(1)圖略.（2）C′(4,3).課后作業(yè)9.C 10.B 11.B 12.(-５，12) 13.25 14.(-1，1)15.圖略，△ABC關(guān)于x軸的對(duì)應(yīng)點(diǎn)分別為A′(-2,1),B′(1,0),C′(0,-1)；△ABC關(guān)于y軸的對(duì)應(yīng)點(diǎn)分別為A″(2,-1),B″(-1,0),C″(0,1).16.(1)B(-3,-2),C(3,-2),D(3,2).(2)由軸對(duì)稱可知,AB，CD都垂直于x軸,BC，AD都垂直于y軸,∴∠A=∠B=∠C=∠D=90°.即四邊形AB