廣西玉林市玉州區(qū)2019屆九年級(jí)數(shù)學(xué)第一次模擬試題(含參考)

廣西玉林市玉州區(qū)2019屆九年級(jí)數(shù)學(xué)第一次模擬試題(含參照答案)廣西玉林市玉州區(qū)2019屆九年級(jí)數(shù)學(xué)第一次模擬試題(含參照答案)13/13廣西玉林市玉州區(qū)2019屆九年級(jí)數(shù)學(xué)第一次模擬試題(含參照答案)玉林市玉州區(qū)2019屆九年級(jí)數(shù)學(xué)第一次模擬試題注意事項(xiàng)：本試卷滿分120分。考試時(shí)間為120分鐘。選擇題每題選出答案后，用2B鉛筆把答題卡上對(duì)應(yīng)題目的選項(xiàng)標(biāo)號(hào)涂黑。非選擇是，用直徑0.5毫米黑色墨水署名筆在答題卡上各題的答題區(qū)地域內(nèi)作答，答在式試卷上無(wú)效?？荚嚱Y(jié)束，將本試卷和答題卡一并交回。一、選擇題：本大題共12小題，每題3分，共36分。在每題給出的四個(gè)選項(xiàng)中，只有一項(xiàng)為哪一項(xiàng)符合題目要求的，把正確答案的標(biāo)號(hào)填（涂）在答題卡內(nèi)相應(yīng)的地點(diǎn)上。1.1的倒數(shù)等于（）2A.2B.2C.1D.1222.以下四個(gè)圖形中，既是軸對(duì)稱圖形又是中心對(duì)稱圖形的是（）ABCD國(guó)家開(kāi)發(fā)銀行2018年有力有序落實(shí)“一帶一路”2500億元專項(xiàng)貸款，落實(shí)“十三五”規(guī)劃，全面提高國(guó)際發(fā)展質(zhì)量。此中2500億用科學(xué)記數(shù)法表示為（）A.251010B.2.51010C.2.51011D.0.2510124.使分式x1值為零的x的值為（）x1A.1B.0C.1D.25.從一副撲克牌中隨機(jī)抽出一張牌，獲取方塊或許A的概率是（）A.17B.17C.8D.16525427526.以以下圖，將RtABC繞點(diǎn)A按順時(shí)針旋轉(zhuǎn)必定角度獲取RtADE，點(diǎn)B的對(duì)應(yīng)點(diǎn)D恰巧落在BC邊上，若AB1，C30，則CD的長(zhǎng)為（）第6題圖A.1B.1.5C.2D.2217.一組的眾數(shù)、中位數(shù)、方差分別是（）A.4,3,0.2B.3,3,0.4C.3,4,0.2D.3,2,0.48.以下計(jì)算中，正確的選項(xiàng)是（）A.2a2b2B.a6a3a3abC.2x2y36x6y3D.2369.如圖，在RtABC中，C90，AB5，BC4，則以下三角函數(shù)表示正確的選項(xiàng)是（）第9題圖A.tanA3B.tanB43D.cosA34C.sinA53510.中國(guó)“一帶一路”戰(zhàn)略沿線國(guó)家和地域帶來(lái)很大的經(jīng)濟(jì)效益，沿線某地域居民2017年人均收入為300美元，估計(jì)2019年人均收入將達(dá)到1200美元，設(shè)2017年到2019年該地域居民年人均收入均勻增加率為x，可列方程為（）A.30012x1200C.3001x21200

B.3001x21200D.3002x120011.如圖，將O沿弦MN折疊，圓弧恰巧經(jīng)過(guò)圓心O，點(diǎn)A劣弧MN上一點(diǎn)，則MAN的度數(shù)為（）A.150B.135C.120D.10512.y24（h為常數(shù)），在自變量x的值知足1≤x≤4的狀況下，與其對(duì)應(yīng)的函已知二次函數(shù)xh數(shù)值y的最大值為0，則h的值為（）A.1和6B.2和6C.1和3D.2和3二、填空題：本大題共6小題，每題3分，共18分，把答案填在答題卡的橫線上。13.使二次根式x2在實(shí)數(shù)范圍內(nèi)存心義的x的取值范圍是；14.分解因式：2xy218x；215.假如a2b1c32bc；0，那么a16.假如點(diǎn)A1,4，Bm,4在拋物線yax12；h上，那么m的值為17.如圖，母線長(zhǎng)為33的圓錐的側(cè)面張開(kāi)圖是一個(gè)扇形，若圓錐的底面圓半徑是3，則張開(kāi)圖扇形的圓心角底數(shù)為；第17題圖18.如圖，正方形ABCD的邊長(zhǎng)為10，點(diǎn)M在AD上，AM8，過(guò)M作MN∥AB，分別交AC、BC于H、N兩點(diǎn)，若E、F分別為CH、BM的中點(diǎn)，則EF的長(zhǎng)為第18題圖三、解答題：本大題共8小題，滿分66分，解答過(guò)程寫在答題卡上，解答寫出文字說(shuō)明，證明過(guò)程或演算步驟。1119.（6分）計(jì)算：02019259120.（6分）化簡(jiǎn)x1x1x1x2xx

2，并從1,0,1,2中選擇一個(gè)適合的數(shù)求代數(shù)式值。21.（6分）如圖，ABC三個(gè)極點(diǎn)的坐標(biāo)分別為A1,1,B4,2,C3,4.（1）請(qǐng)畫出ABC向左平移6個(gè)單位長(zhǎng)度后獲取的A1B1C1；（2）請(qǐng)畫出A1B1C1對(duì)于原點(diǎn)對(duì)稱的A2B2C2；（3）請(qǐng)x軸上求作一點(diǎn)D，使DA1B1的周長(zhǎng)最小，請(qǐng)畫出DA1B1，并直接寫出D的坐標(biāo).322.（8分）某班為認(rèn)識(shí)學(xué)生每周進(jìn)行體育鍛煉的時(shí)間狀況，對(duì)全班60名學(xué)生進(jìn)行檢查，按每周進(jìn)行體育鍛煉的時(shí)間t（單位：小時(shí)），將學(xué)生疏成五類：A類0≤t≤2，B類2t≤4，C類4t≤6，D類6t≤8，E類t8.繪制成尚不圓滿的條形統(tǒng)計(jì)圖如圖.依據(jù)以上信息，解答以下問(wèn)題：（1）E類學(xué)生有人，補(bǔ)全條形統(tǒng)計(jì)圖；（2）D類學(xué)生人數(shù)占被檢查總?cè)藬?shù)的%；（3）從該班每周進(jìn)行體育鍛煉時(shí)間在0≤t≤4的學(xué)生中任選人2人，求這2人每周進(jìn)行體育鍛煉時(shí)間都在2t≤4中的概率.23.（8分）如圖，已知AB是O的直徑，AC是O切線，連結(jié)BC交O于點(diǎn)P，且P為BC中點(diǎn)。1）求證：ABAC；2）若O的直徑長(zhǎng)為8，①求弧BP的長(zhǎng)；②求暗影部分的面積.24.（10分）蔬菜基地栽種了娃娃菜和油菜兩種蔬菜共30畝，設(shè)栽種娃娃菜x畝，總利潤(rùn)為y萬(wàn)元，相關(guān)數(shù)據(jù)見(jiàn)下表：4成本（單位：萬(wàn)元/畝）銷售額（單位：萬(wàn)元/畝）娃娃菜2.43油菜22.5（1）求y對(duì)于x的函數(shù)關(guān)系式（利潤(rùn)=銷售額–成本）；（2）若計(jì)劃投入的總成本不超出70萬(wàn)元，要使獲取的總利潤(rùn)最大，基地應(yīng)栽種娃娃菜和油菜各多少畝？（3）已知娃娃菜每畝地需要化肥400kg，油菜每畝地需要化肥600kg，依據(jù)（2）中的栽種畝數(shù)，基地計(jì)劃運(yùn)送所需所有化肥，為了提高效率，實(shí)質(zhì)每次運(yùn)送化肥的總量是原計(jì)劃的1.25倍，結(jié)果運(yùn)送圓滿部化肥的次數(shù)比原計(jì)劃少1次，求基地原計(jì)劃每次運(yùn)送多少化肥.（10分）如圖1，在正方形ABCD中，E，F(xiàn)分別為BC，CD的中點(diǎn)，連結(jié)AE，EF，交點(diǎn)為G.若正方形的邊長(zhǎng)為4.圖1（1）求證：AEBF；（2）將BCF沿BF對(duì)折，獲取BPF（如圖2），延伸FP交BA的延伸線于點(diǎn)Q，求AQ的長(zhǎng)；圖2（3）將ABE繞點(diǎn)A逆時(shí)針?lè)较蛐D(zhuǎn)，使邊AB正好落在AE上，獲取AHM（如圖3），若AM和BF訂交于點(diǎn)N，求四邊形MNGH面積.圖326.（12分）已知：如圖，直線y1xb與x軸負(fù)半軸交于點(diǎn)A，與y軸正半軸交于點(diǎn)B，線段OA的長(zhǎng)25是方程x27x80的一個(gè)根，請(qǐng)解答以下問(wèn)題：（1）求點(diǎn)B的坐標(biāo)；（2）雙曲線ykk0,x0與直線AB交于點(diǎn)C，且AC55，求k的值；x（3）在（2）的條件下，點(diǎn)E在線段AB上，AE55，直線ly軸，垂足為P0,7，點(diǎn)M在直線l上，在直線AB上的坐標(biāo)平面內(nèi)能否存在點(diǎn)N，使以點(diǎn)C、E、M、N為極點(diǎn)的四邊形是矩形？若存在，懇求出點(diǎn)N的坐標(biāo)；若不存在，請(qǐng)說(shuō)明原因。2019年玉州區(qū)第一次中考模擬試題數(shù)學(xué)參照答案一、ACCACABBDBCA二、13.x≥214.2xy3y315.216.317.12018.4118題解答過(guò)程：過(guò)F作FGBC于點(diǎn)G，過(guò)E作EPBC于點(diǎn)P，EHFG于點(diǎn)H∵四邊形ABCD是正方形∴AD∥BC，BC10MN∥AB∴四邊形ABNM是矩形∴BNAM8，MN10∴CN2∵AC是正方形ABCD的對(duì)角線∴CHNHCN45m]MNCN2∵E、F分別為CH、BM的中點(diǎn)6又∵FGBC，EPBC，EHFG∴EQEP1，F(xiàn)G5，BGNG4∴GHEP1，QHNG4∴EHEQQH5，F(xiàn)HFGGH4在RtEFH中，EFEH2FH2425241三、19.解：原式2191·····················································4分2131·····················································5分·····························································6分x1x220.解：11x2xxxx1xx1xx1x21x21xxx1x1

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·······················································3分1·······································································4分x1∵x0，且x10，且x10∴x0，且x1，且x1∴在1,0,1,2中，x的值只好取2∴原式211·······························································6分1321.（1）以以下圖，A1B1C1為所求作的三角形·········································2分（2）以以下圖，A2B2C2所求作的三角形············································4分（3）以以下圖，DA1B1為所求作的三角形，點(diǎn)D坐標(biāo)為（4,0）························6分722.解：（1）15，補(bǔ)全圖形以下：···················································2分（2）30·········································································4分（3）∵每周進(jìn)行體育鍛煉時(shí)間在0≤t≤2內(nèi)的兩人記為甲、乙，在2＜t≤4內(nèi)的3人記為A、B、C，從中任選兩人有：甲乙、甲A、甲B、甲C、乙A、乙B、乙C、AB、AC、BC這10種可能結(jié)果，此中2人每周進(jìn)行體育鍛煉時(shí)間都在2＜t≤4中的有AB、AC、BC這3種結(jié)果∴這2人每周進(jìn)行體育鍛煉時(shí)間都在2＜t≤4中的概率為3······························8分10（1）證明：連結(jié)APAB是O的直徑∴APB90∴APBCP為BC中點(diǎn)∴AP垂直均分BC∴ABAC········································································3分（2）①連結(jié)PO]∵AC是O的切線，AB是O的直徑∴ABACCAB90∵ABAC,APBC∴PAB145CAB28POB2PAB90O的直徑長(zhǎng)為8O的半徑長(zhǎng)為4∴弧BP的長(zhǎng)2···································································6分②∵POB90，OBOP4∴SPOB8，S扇形POB4∴暗影扇形POBSPOB48························································8分SS24．解：（1）由題意得y(32.4)x(2.52)(30x)0.1x15；·························3分（2）由題意知2.4x2(30x)≤70，解得x≤25·······································5分對(duì)于y0.1x15，∵0.10，∴y隨x的增大而增大，∴當(dāng)x25時(shí)，所獲總利潤(rùn)最大，此時(shí)30x5.答：基地應(yīng)栽種娃娃菜25畝，栽種油菜5畝；·············································6分（3）設(shè)原計(jì)劃每次運(yùn)送化肥zkg，實(shí)質(zhì)每次運(yùn)送1.25zkg，需要運(yùn)送的化肥總量是40025600513000（kg），由題意可························································8分z1.25z解得z2600.經(jīng)查驗(yàn)，z2600是原分式方程的解．答：基地原計(jì)劃每次運(yùn)送化肥2600kg···················································10分解：（1）證明：如圖1，∵E，F(xiàn)分別是正方形ABCD邊BC，CD的中點(diǎn)，CFBE，在RtABE和RtBCF中，ABBCABEBCF，BECF∴RtABE≌RtBCF（SAS），·······················································2分BAECBF，又∵BAEBEA90，9∴CBFBEA90，BGE90，∴AEBF.······································································3分圖1（2）解：如圖2，依據(jù)題意得，F(xiàn)PFC，PFBBFC，F(xiàn)PB90CD∥AB，∴CFBABF，∴ABFPFB，QFQB，∵PFFC2，PBBC4，·····················································5分在RtBPQ中，設(shè)QBx，∴x2242，（x-2）x5，∴AQBQAB541．·························································6分圖2（3）解：∵正方形邊長(zhǎng)為4，∵BAEEAM，AEBF，∴ANAB4，AHM90，GN∥HM，·····································································8分AGN∽AHM10SS

2AGNANAHMAM2∴SAGN244516∴SAGN，5∴S四邊形GHMNSAHMSAGN4164，55∴四邊形GHMN的面積是4．························································10分526.解：(1)解方程x27x80得x8或x-1.∵線段OA的長(zhǎng)是方程x27x80的一個(gè)根，OA的長(zhǎng)是正數(shù)∴OA8，∴A8,0．將A8,0代入y=1x+b，得4b0，2∴b4，∴B0,4．············································································3分（2）在RtAOB中，OA8，OB4，∴AB45.圖1如圖①，過(guò)點(diǎn)C作CHx軸于點(diǎn)H，則CH∥OB，11AOB∽AHC·····································································5分∴OBABOA即4458CHACOHCH55AH解得CH5，AH10，∴OH1082，∴C2,5．∵雙曲線（ykk0,x0）經(jīng)過(guò)點(diǎn)C，x∴k2510························