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1绵阳南山中学2023年高一新生入学考试数学试卷参考答案及评分标准一、选择题(每个小题3分,共36分)题号123456789101112选项ACBABDADCBDC二、填空题(每个小题4分,共24分)13.42614.21615.-116.1817.
5或218.2022.5三、解答:(共90分)19.解(1)原式43335143·····················································8分(2)原式4411xxxx
·············································································4分把52x代入得原式44(51)5151(51)(51)······························
··8分20.解(1)∵总人数302000.15(人)∴2000.4590m,600.3200n.……………………………………………3分(2)由(1)的计算知70至80分段的人数为90人,………………………4分90至100分段的人数
20030906020人,补全条形图如下图所示:……………………………………6分(3)比赛成绩的中位数落在:70~80分…………………………………9分(4)恰好抽中获奖选手的概率为:602022005.…………………………12分21.解(1)由
bkbk321,解得3534bk,所以3534xy································3分5(0)4C,,5(0)3D,.在Rt△OCD中,35OD,45OC,···············
····················5分∴OCDtan34OCOD.·········································································6分频数1209060300分数(分)90100806070
202(2)取点A关于原点的对称点(21)E,,则问题转化为求证45BOE.由勾股定理可得,5OE,5BE,10OB,∵222BEOEOB,∴△EOB是等腰直角三角形.∴45BOE.∴13
5AOB°…………………12分22.解(1)设改造一所A类学校和一所B类学校所需的改造资金分别为a万元和b万元.依题意得:22302205abab··········································
···························2分解之得6085ab···················································································3分答:改造一所A类学校和一所B类学校
所需的改造资金分别为60万元和85万元········································································································4分(2)设该县有A、B两
类学校分别为m所和n所.则60851575mn···········································································
····5分173151212mn················································································6分∵A类学校不超过5所∴1731551215n≤∴15n≥即:B类学校至少有
15所.·································································8分(3)设今年改造A类学校x所,则改造B类学校为6x所,依题意得:
507064001015670xxxx≤≥·······································································10分解之得14x≤≤·······
···········································································11分∵x取整数∴1234x,,,即:共有4种方案.································
···········12分23.证明(1):∵AB是直径∴90ACB,90CABABC……………2分∵MACABC∴90MACCAB,即MAAB∴MN是半圆的切线.…………………………4分(2)如图∵DAC是弧的中点,
∴DBCDBA……………………………5分∵AB是直径∴90ACB,故90DBCCGB∵DEAB,∴90DBAFDG,∴FDGCGBFGD∴FDFG…………………………………………………………………8分(3)连结AD则90AD
B,∵DEAB,DAC是弧的中点∴ADFDBADAF∴AFDFFG………………………………………………………………9分∴29ADGDFGSS……………………………………………………………10分又∵90ADGBCGDGACGB,∴ADGBC
G∽………………………………………………………………11分∴22416()()39BCGADGSCGSDG∴169169BCGS.……………………………………………………………12分(其它解法,请酌情评分)24.解(1)∵点(
1,0)B,3OCOB,(0,3)C…………………………………1分MNAEDCGBF342-5xyAONMGFE把1,0B、(0,3)C代入23yaxaxc得:330caac解得:334ac,∴所求抛物线的解析式为239344yxx
……………………………………2分(2)过点D作DM∥y轴分别交线段AC和x轴于点MN、.∵对称轴3322axa,1,0B,∴点(4,0)A∴ABCACDABCDSSS四边形=111553()2222DMANONDM
=易得直线AC的解析式为334yx…………………4分令239(3)44Dxxx,,3(3)4Mxx,,其中40x,2233933(3)(2)34444DMxxxx………6分当2x时,DM有最大值3此时四边形AB
CD面积有最大值272.…………………7分(3)如图,有如下情况:①过点C作1CP∥x轴交抛物线于点1P,过点1P作11PE∥AC交x轴于点1E,此时四边形11ACPE为平行四边形,∵(03)C,,令2393344xx得:1203xx
,∴点1(33)P,……………………………………9分②平移直线AC交x轴于点E,交x轴上方的抛物线于点P,当ACPE时,四边形ACEP为平行四边形,∵(03)C,,∴由对称关系令(3)Px,,由2393344xx化简得:2380xx,解得3412x
或3412x,此时存在点2341(3)2P,和3341(3)2P-,…………………………11分综上,存在3个点符合题意,坐标分别是1(33)P,,2341(3)2P,,3341(3)2P-,.…………………………12分25.(1)△A
MN是直角三角形.……1分依题意得OA=2,OM=4,ON=1,∴MN=OM+ON=4+1=5在Rt△AOM中,AM=22OAOM=2224=25在Rt△AON中,AN=22OAON=2221=5ABCDxyNMOABCxy2
P1P3P1E2E3EO442-55FGEPlAxyONMB42-2-4-6-55GFEQ2Q1PlAxyONM∴MN2=AM2+AN2∴△AMN是直角三角形(解法不惟一)………………………3分(2)答:(1)中的结论还成立.……
……………………………4分依题意得OA=2,OM=-m,ON=n∴MN=OM+ON=n-m∴MN2=(n-m)2=n2-2mn+m2∵mn=-4∴MN2=n2-2×(-4)+m2=n2+m2+8又∵在Rt△AOM中,AM=22OAOM=222()m=24m在Rt△AON中,AN=
22OAON=222n=24n∴AM2+AN2=4+m2+4+n2=n2+m2+8∴MN2=AM2+AN2∴△AMN是直角三角形.(解法不惟一)………………6分(3)∵mn=-4,n=4,∴1m.方法一:设抛物线的函数关系式为y=ax2+bx+c.∵抛物线经过点M(
-1,0)、N(4,0)和A(0,2)2a-bc04402abcc12322abc∴所求抛物线的函数关系式为y=-12x2+32x+2.………………8分方法二:设抛物线的函数关系式为
y=a(x+1)(x-4).∵抛物线经过点A(0,2)∴-4a=2解得a=-12∴所求抛物线的函数关系式为y=-12(x+1)(x-4)即y=-12x2+32x+2.……………8分(4)抛物线的对称轴与x轴的交点Q1符合
条件,∵l⊥MN,∠ANM=∠PNQ1,∴Rt△PNQ1∽Rt△ANM∵抛物线的对称轴为x=32,∴Q1(32,0)………………10分∴NQ1=4-32=52.………………11分过点N作NQ2⊥AN,交抛物线的对称轴于点Q2.∴Rt△PQ2N、Rt△NQ2Q1、Rt△PNQ1和Rt
△ANM两两相似∴AMNQANQQ121即Q1Q2=221522455QNANAM…………12分∵点Q2位于第四象限,∴Q2(32,5)…………13分因此,符合条件的点有两个,分别是Q1(32,0)
,Q2(32,5).…………14分(解法不惟一)获得更多资源请扫码加入享学资源网微信公众号www.xiangxue100.com