湖南省岳阳市2022-2023学年数学九年级第一学期期末监测模拟试题含解析

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2022-2023
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14(2)ᵫÍÚÛh+b>YḄxḄ<>xV-3ᡈ0VxV6FX(3)EḄᙶ᪗(0,a),VA(-3,4),O(0,0),.,.OE=\a\,OA=5,AE=^9+(«(-4)2>•••HAOEJÜῪ!"#[জMOA=OE|a|=5,••u±5f.P(0,5)ᡈ(0,-5),ঝMOA=AE5=j9+(a-4)2,஺=8ᡈ஻=0(ß).P(0,8),ঞMOE=AE|aÂj9+(a-4)2,258,25ஹ.P(0,—),825ᓽPÛᩩâḄÂḄᙶ᪗Â(0,5)ᡈ(0,-5)ᡈ(0,8)ᡈ(0,—OூR௃C⚪JÅlÆ0ᦪãᔠ⚪ä⌕ὃVWåH3ᦪæ┦"!"0ᦪÜῪ!"#Ḅឋéᵨ]^ḄêëXì⚪JXT⚪Ḅᐵ.lEF221ஹ(1)DC-25/3;(2)=ூX᪆௃(D8ND4C=INBAC=30°,ᙠRtZ\ADC¯ᵫ!"0ᦪ¨8OC=AC-tan30஺=2í(2)ᵫ!"0ᦪ¨8BC=AC“an60o==6í¨88஺=6C-CO=4íîïHDFMðZXAGM(ASA),¨8DF=AG,ᵫ-.ᑖᡂlÆHᳮ¨8ᓽw¨8Aᫀ.ூxX௃XP(1)•.•AO-ᑖZR4C,Zfi4C=60o,.ZDAC^-ZBAC^30°,2ᙠAADC¯£>C=ACtan30°=2G(2)VZC=90°,AC=6,ZBAC=60°,

15ABC=ACgtan60°=6xV3=65/3:.BD=BC-CD=46,VDE/7AC,NDMF%NAMGDJ⚔,.,.ZFDM=ZGAM,ZDMF=ZAMG,••,MDNOADḄP,.AM=DM,ZFDM=ZGAM?ᐰḄឋ"TᑨᱯVḄWᦪYD1⚪Ḅᐵ[.22ஹ
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11F᝞t஺0ᓽeᡠ}.VZA=ZB=30°,.•.ZACB=180°-30°-30°=120°,

16PMNᚖ6-ᑖ'AC,.*.OA=OC,.•.ZA=ZACO=30°,.,.ZOCB=90°,.,.OC±BC,BCJ஺஺Ḅᑗ.ூR௃T⚪ä⌕ὃVḄJòóḄ]æôᙊḄãᔠ`ᵨabᙠòóḄ᎛◤⌕÷ᶇùú.223ஹY3ூX᪆௃û⚪ᑖ᪆P"Ḅ!"0ᦪwüᓄ6"!"#GḄl)*OC᪷tuᡠḄᙊᕜ"'Ü,ýwüᓄP6"!"#Ḅ┦"Ḅ!"0ᦪḄ⚪.AC2û⚪X᪆PXP)*OC.J6AZACD=90°.Y2B=ND,AsinB=sinD=——=-.AD3RPãᔠᵨWᙊᕜ"Hᳮôᐸÿ.Ḅ┦ᦪ᪷ᩩᓄᑮ.24ஹ20%ூ᪆௃"⚪ᑖ᪆%&'()*+,-ᙳ*+᳛Ḅ0⚪12345ᩭḄ7ᦪ*+8Ḅ9:.;<(,Ḅ,-ᙳ*+᳛=x,ᑣ&'()*+?8@A✂ᨵA10(1+x)2DEᓽGᑡIJ."⚪᪆%;<(,@AEᦪḄ,-ᙳ*+᳛=X.᪷⚪K10(1+x)2=14.4Kxi=0.2=20%,X2=-2.2(MNᔠ⚪PQ).S%<(,@AEᦪḄ,-ᙳ*+᳛=20%.25ஹ(1)20%(2)y=30m(3)ᖪU=VWᜩYᑭᨬᜧWᓟ^1_`7ᐗூᑖ᪆௃(1);W)b`Ḅcᑖ᳛=x,᪷⚪ᑡdIJᓽGe(2)᪷⚪ᑡdᦪ⊤ghᓽGe

17(3)᪷ijᐵlᑡdᦪ᪆hᯠ8᪷᪆hḄឋodᨬpᓽG.ூq௃%(D;W)b`Ḅcᑖ᳛=x,᪷⚪K%25(1+x)2=36,K%x=0.2=20%,x,=-2.2(Mᔠ⚪PQ)S%W)b`Ḅcᑖ᳛20%I(2);r=14171,t=3,y=90uᐭK90=3%,/.k=30,r.ywmḄᦪ᪆h=y=30mI(3)x⚪ᨵw=(15-m)x30m=450m-30m2=-30m2+450m,b450)ua=-30<0,yᱥ{Ḅ|}ᔣ=஻?==~2x(-30)=7-5,<7.5wmḄ*ᜧ*ᜧ02(2)᝞@2,'Q¥xᚖ{ᚖ®=H,ᑣQH=AQsin62o=G(3T).◤⌕ᑖ%APHQ^AABC,2

18BPF3-^+/KPHHQt=233>/3±ᳮAQIlPsaABCt=2.³´ᡠ¶t=2ᡈt=2(3)᝞@2,'Q¥QN஻OB¦x§N,NQNA=NBOA=62o=/QAN,QN=QA,.,.AQN=iOEPO/.NQ=NA=AQ=3-t,.*.ON=3-(3-t)=t,PN=t+t=2t,AOE/7QN,/.POE^APNQ,A—;=—,QNPNE[31]3——=-,;.OE=---t,VEF/7xtt,/.ZBFE=ZBCO=ZFBE=32°,/.EF=BE,.,.m=BE=OB-OE==-Z+-3-r22222@1@2ὃ%·¸³ᔠ⚪.