2019年云南省數(shù)學(xué)中考試題

-/r/n.z./r/n2019/r/n年云南省初中學(xué)業(yè)水平考試/r/n數(shù)學(xué)試題/r/n一、填空題（本大題共/r/n6/r/n小題，每小題/r/n3/r/n分，共/r/n18/r/n分）/r/n1./r/n若零上/r/n8/r/n℃/r/n記作＋/r/n8/r/n℃/r/n，則零下/r/n6/r/n℃/r/n記作/r/n℃/r/n./r/n2./r/n分解因式：/r/n*/r/n2/r/n－/r/n2/r/n*/r/n＋/r/n1/r/n＝/r/n./r/n3./r/n如圖，若/r/nAB/r/n∥/r/nCD/r/n，/r/n∠/r/n1/r/n＝/r/n40/r/n度，/r/n則/r/n∠/r/n2/r/n＝度/r/n./r/n4./r/n若點（/r/n3/r/n，/r/n5/r/n）在反比例函數(shù)/r/n的圖象上，則/r/nk/r/n＝/r/n./r/n5./r/n*中學(xué)九年級甲、乙兩個班參加了一次數(shù)學(xué)考試，考試人數(shù)每班都為/r/n40/r/n人，每個班的考/r/n試成績分為/r/nA/r/n、/r/nB/r/n、/r/nC/r/n、/r/nD/r/n、/r/nE/r/n五個等級，繪制的統(tǒng)計圖如下：/r/n根據(jù)以上統(tǒng)計圖提供的信息，則/r/nD/r/n等級這一組人數(shù)較多的班是/r/n./r/n6./r/n在平行四邊形/r/nABCD/r/n中，/r/n∠/r/nA/r/n＝/r/n30/r/n°/r/n，/r/nAD/r/n＝/r/n43/r/n，/r/nBD/r/n＝/r/n4/r/n，則平行四邊形/r/nABCD/r/n的面積等于/r/n./r/n二、選擇題（本大題共/r/n8/r/n小題，每小題只有一個正確選項，每小題/r/n4/r/n分，共/r/n32/r/n分）/r/n7./r/n下列圖形既是軸對稱圖形，又是中心對稱圖形的是/r/n8.2019/r/n年"五一/r/n”/r/n期間，*景點接待海內(nèi)外游客共/r/n688000/r/n人次，/r/n688000/r/n這個數(shù)用科學(xué)記/r/n數(shù)法表示為/r/n×/r/n10/r/n4/r/n×/r/n10/r/n6/r/n×/r/n10/r/n5/r/n×/r/n10/r/n6/r/n9./r/n一個十二邊形的內(nèi)角和等于/r/nA.2160/r/n°/r/n/r/nB.2080/r/n°/r/nC.1980/r/n°/r/nD.1800/r/n°/r/ny/r/n10./r/n要使/r/n有意義，則/r/n*/r/n的取值范圍為/r/nA./r/n*/r/n≤/r/n0/r/nB./r/n*/r/n≥/r/n－/r/n1C./r/n*/r/n≥/r/n0D./r/n*/r/n≤/r/n－/r/n1/r/n11./r/n一個圓錐的側(cè)面展開圖是半徑為/r/n8/r/n的半圓，則該圓錐的全面積是/r/nA.48/r/nπ/r/nB.45/r/nπ/r/nC.36/r/nπ/r/nD.32/r/nπ/r/n12./r/n按一定規(guī)律排列的單項式：/r/n*/r/n3/r/n，－/r/n*/r/n5/r/n，/r/n*/r/n7/r/n，－/r/n*/r/n9/r/n，/r/n*/r/n11/r/n，/r/n……/r/n第/r/nn/r/n個單項式是/r/nA./r/n（－/r/n1/r/n）/r/nn/r/n－/r/n1/r/n*/r/n2n/r/n－/r/n1/r/nB./r/n（－/r/n1/r/n）/r/nn/r/n*/r/n2n/r/n－/r/n1/r/nC./r/n（－/r/n1/r/n）/r/nn/r/n－/r/n1/r/n*/r/n2n/r/n＋/r/n1/r/nD./r/n（－/r/n1/r/n）/r/nn/r/n*/r/n2n/r/n＋/r/n1/r/n13./r/n如圖，/r/n△/r/nABC/r/n的內(nèi)切圓/r/n⊙/r/nO/r/n與/r/nBC/r/n、/r/nCA/r/n、/r/nAB/r/n分別相切于點/r/nD/r/n、/r/nE/r/n、/r/nF/r/n，且/r/nAB/r/n＝/r/n5/r/n，/r/nBC/r/n＝/r/n13/r/n，/r/nCA/r/n＝/r/n12/r/n，則陰影部分（即四邊形/r/nAEOF/r/n）的面積是/r/nA.4/r/nB.6.25/r/nC.7.5/r/nD.9/r/n14./r/n若關(guān)于/r/n*/r/n的不等式組/r/n的解集為/r/n*/r/n＞/r/na/r/n，則/r/na/r/n的取值范圍是/r/nA./r/na/r/n＜/r/n2B./r/na/r/n≤/r/n2/r/nC./r/na/r/n＞/r/n2D./r/na/r/n≥/r/n2/r/n三、解答題（本大題共/r/n9/r/n小題，共/r/n70/r/n分）/r/n15./r/n（本小題滿分/r/n6/r/n分）/r/n計算：/r/n16./r/n（本小題滿分/r/n6/r/n分）/r/n如圖，/r/nAB/r/n＝/r/nAD/r/n，/r/nCB/r/n＝/r/nCD./r/n求證：/r/n∠/r/nB/r/n＝/r/n∠/r/nD./r/n17./r/n（本小題滿分/r/n8/r/n分）/r/n*公司銷售部有營業(yè)員/r/n15/r/n人，該公司為了調(diào)動營業(yè)員的積極性，決定實行目標(biāo)管理，根據(jù)目標(biāo)完成的情況對營業(yè)員進(jìn)行適當(dāng)?shù)莫剟?，為了確定一個適當(dāng)?shù)脑落N售目標(biāo)，公司有關(guān)部/r/n門統(tǒng)計了這/r/n15/r/n人*月的銷售量，如下表所示：/r/n月銷售量/r/n//r/n件數(shù)/r/n1770/r/n480/r/n220/r/n180/r/n12/r/n0/r/n90/r/n人數(shù)/r/n1/r/n1/r/n3/r/n3/r/n3/r/n4/r/n（/r/n1/r/n）直接寫出這/r/n15/r/n名營業(yè)員該月銷售量數(shù)據(jù)的平均數(shù)、中位數(shù)、眾數(shù)；/r/n（/r/n2/r/n）如果想讓一半左右的營業(yè)員都能達(dá)到月銷售目標(biāo)，你認(rèn)為（/r/n1/r/n）中的平均數(shù)、中位數(shù)、眾數(shù)中，哪個最適合作為月銷售目標(biāo)？請說明理由/r/n./r/n溫馨提示：/r/n溫馨提示：/r/n確定一個適當(dāng)?shù)脑落N售目標(biāo)是一個關(guān)鍵問題，如果目標(biāo)定得太高，多數(shù)營業(yè)員完不成任務(wù)，會使?fàn)I業(yè)員失去信心；如果目標(biāo)定得太低，不能發(fā)揮營業(yè)員的潛力。/r/n18./r/n（本小題滿分/r/n6/r/n分）/r/n為進(jìn)一步營造掃黑除惡專項斗爭的濃厚宣傳氛圍，推進(jìn)平安校園建設(shè)，甲、乙兩所學(xué)校各租用一輛大巴車組織部分師生，分別從距目的地/r/n240/r/n千米和/r/n270/r/n千米的兩地同時出發(fā)，前往"研學(xué)教育/r/n”/r/n基地開展掃黑除惡教育活動，已知乙校師生所乘大巴車的平均速度是甲校師/r/n生所乘大巴車的平均速度的/r/n1.5/r/n倍，甲校師生比乙校師生晚/r/n1/r/n小時到達(dá)目的地，分別求甲、乙兩所學(xué)校師生所乘大巴車的平均速度/r/n./r/n19./r/n（本小題滿分/r/n7/r/n分）/r/n甲、乙兩名同學(xué)玩一個游戲：在一個不透明的口袋中裝有標(biāo)號分別為/r/n1/r/n，/r/n2/r/n，/r/n3/r/n，/r/n4/r/n的四個小球（除標(biāo)號外無其它差異）/r/n./r/n從口袋中隨機(jī)摸出一個小球，記下標(biāo)號后放回口袋中，充分搖勻后，再從口袋中隨機(jī)摸出一個小球，記下該小球的標(biāo)號，兩次記下的標(biāo)號分別用/r/n*/r/n、/r/ny/r/n表示/r/n./r/n若/r/n*/r/n＋/r/ny/r/n為奇數(shù)，則甲獲勝；若/r/n*/r/n＋/r/ny/r/n為偶數(shù)，則乙獲勝/r/n./r/n（/r/n1/r/n）用列表法或樹狀圖法（樹狀圖也稱樹形圖）中的一種方法，求（/r/n*/r/n，/r/ny/r/n）所有可能出現(xiàn)的結(jié)果總數(shù)；/r/n（/r/n2/r/n）你認(rèn)為這個游戲?qū)﹄p方公平嗎？請說明理由/r/n./r/n20./r/n（本小題滿分/r/n8/r/n分）/r/n如圖，四邊形/r/nABCD/r/n中，對角線/r/nAC/r/n、/r/nBD/r/n相交于點/r/nO/r/n，/r/nAO/r/n＝/r/nOC/r/n，/r/nBO/r/n＝/r/nOD/r/n，且/r/n∠/r/nAOB/r/n＝/r/n2/r/n∠/r/nOAD./r/n（/r/n1/r/n）求證：四邊形/r/nABCD/r/n是矩形；/r/n（/r/n2/r/n）若/r/n∠/r/nAOB/r/n∶∠/r/nODC/r/n＝/r/n4/r/n∶/r/n3/r/n，求/r/n∠/r/nADO/r/n的度數(shù)/r/n./r/n21./r/n（本小題滿分/r/n8/r/n分）/r/n已知/r/nk/r/n是常數(shù)，拋物線/r/ny/r/n＝/r/n*/r/n2/r/n＋（/r/nk/r/n2/r/n＋/r/nk/r/n－/r/n6/r/n）/r/n*/r/n＋/r/n3/r/nk/r/n的對稱軸是/r/ny/r/n軸，并且與/r/n*/r/n軸有兩個交點/r/n./r/n（/r/n1/r/n）求/r/nk/r/n的值：/r/n（/r/n2/r/n）若點/r/nP/r/n在拋物線/r/ny/r/n＝/r/n*/r/n2/r/n＋（/r/nk/r/n2/r/n＋/r/nk/r/n－/r/n6/r/n）/r/n*/r/n＋/r/n3/r/nk/r/n上，且/r/nP/r/n到/r/ny/r/n軸的距離是/r/n2/r/n，求點/r/nP/r/n的坐標(biāo)/r/n./r/n22./r/n（本小題滿分/r/n9/r/n分）/r/n*駐村扶貧小組實施產(chǎn)業(yè)扶貧，幫助貧困農(nóng)戶進(jìn)行西瓜種植和銷售/r/n./r/n已知西瓜的成本為/r/n6/r/n元/r/n//r/n千克，規(guī)定銷售單價不低于成本，又不高于成本的兩倍/r/n./r/n經(jīng)過市場調(diào)查發(fā)現(xiàn)，*天西瓜的銷售量/r/ny/r/n（千克）與銷售單價/r/n*/r/n（元/r/n//r/n千克）的函數(shù)關(guān)系如下圖所示：/r/n（/r/n1/r/n）求/r/ny/r/n與/r/n*/r/n的函數(shù)解析式（也稱關(guān)系式）；/r/n（/r/n2/r/n）求這一天銷售西瓜獲得的利潤的最大值/r/n./r/n23./r/n（本小題滿分/r/n12/r/n分）/r/n如圖，/r/nB/r/n是/r/n⊙/r/nC/r/n的直徑，/r/nM/r/n、/r/nD/r/n兩點在/r/nAB/r/n的延長線上，/r/nE/r/n是/r/nOC/r/n上的點，且/r/nDE/r/n2/r/n＝/r/nDB/r/n·/r/nDA./r/n延長/r/nAE/r/n至/r/