【新】2019-2020沪科版八年级数学上册期末考试测试卷及答案

1一、选择题（本大题共10小题，共40分）1.点,1(P)2关于y轴对称的点的坐标是()hisarticleincludessomeparts,includinA.(1,2)B.(－1,2)C.(－1,－2)D.(－2,1)2.有一个角是的等腰三角形，其它两个角的度数是()hisarticleincludessomeparts,includinA.36°,108°B.36°,72°hisarticleincludessomeparts,includinC.72°,72°D.36°,108°或72°,°72°3.点P在x轴的下方，且距离x轴3个单位长度，距离y轴4个单位长度，则点P的坐标为()hisarticleincludessomeparts,includinA.(4,－3)B.(3,－4)C.(－3,－4)或(3,－4)D.(－4,－3)或(4,－3)hisarticleincludessomeparts,includin4.若三条线段中3a，5b，c为奇数，那么由a、b、c为边组成的三角形共有()A.1个B.3个C.无数多个D.无法确定hisarticleincludessomeparts,includin5.在同一直角坐标系中，若直线3kxy与直线bxy2平行，则()A.2k，3bB.2k，3bC.2k,3bhisarticleincludessomeparts,includinD.2k,3b6.当0k,0b时，函数bkxy的图象大致是()A.B.C.D.7.有以下四个命题：其中正确的个数为()hisarticleincludessomeparts,includin学校姓名班级___________座位号……装…………订…………线…………内…………不…………要…………答…………题……2(1)两条对角线互相平分的四边形是平行四边形;(2)两条对角线相等的四边形是矩形;(3)两条对角线互相垂直的平行四边形是菱形;(4)有一组邻边相等且有一个角是直角的四边形是正方形;A.1B.2C.3D.48.如图，OP是∠AOB的平分线，点P到OA的距离为3，点N是OB上的任意一点，则线段PN的取值范围为()A.3PNB.3PNC.3PND.3PN9.如图，将矩形纸片ABCD折叠，使点D与点B重合，点C落在C处，折痕为EF，若1AB,2BC，则△ABE和FCB的周长之和为()A.3B.4C.6D.810.有下列四个命题：①相等的角是对顶角；②同位角相等；③若一个角的两边与另一个角的两边互相平行，则这两个角一定相等；④从直线外一点到这条直线的垂线段，叫做点到直线的距离其中是真命题的个数有()hisarticleincludessomeparts,includinA.0个B.1个C.2个D.3个hisarticleincludessomeparts,includin二、填空题（本大题共6小题，共18分）hisarticleincludessomeparts,includin11.如图，把“QQ”笑脸放在直角坐标系中，已知左眼A的坐标是(－2,3)，嘴唇C点的坐标为(－1,1)，则此“QQ”笑脸右眼B的坐标_______________．12.如图，在平面直角坐标系xOy中，△CBA由△ABC绕点P旋转得到，则点P的坐标为_______________．第8题图第9题图313.已知函数2)1(nxmy是正比例函数，则n_________hisarticleincludessomeparts,includin14.如图，DCAB，请补充一个条件：_________________使△ABC≌△DCB（填其中一种即可）hisarticleincludessomeparts,includin15.已知：如图，AEAC，21，ADAB，若25D，则B的度数为_____________________．hisarticleincludessomeparts,includin16.如图，已知OC平分AOB，OBCD∥，若cmOD6，则CD的长等于____________．三、计算题（本大题共5小题，共30分）hisarticleincludessomeparts,includin17.在直角坐标平面内，已点A（3，0）、B（－5，3），将点A向左平移6个单位到达C点，将点B向下平移6个单位到达D点．(1)写出C点、D点的坐标：C__________，D____________；(2)把第14题图第12题图第15题图4这些点按ADCBA顺次连hisarticleincludessomeparts,includin接起来，这个图形的面积是__________．hisarticleincludessomeparts,includin18.已知点)12,1(aaP关于x轴的对称点在第一象限，求a的取值范围．hisarticleincludessomeparts,includinhisarticleincludessomeparts,includin19.如图是屋架设计图的一部分，其中30A，点D是斜梁AB的中点，BC、DE垂直于横梁AC,cmAB8，则立柱BC，DE要多长？hisarticleincludessomeparts,includin20.我国西南五省市的部分地区发生严重旱灾，为鼓励节约用水，某市自来水公司采取分5段收费标准，右图反映的是每月收取水费y元与用水量x吨之间的函数关系．hisarticleincludessomeparts,includin(1)小明家五月份用水8吨，应交水费______元；(2)按上述分段收费标准，小明家三、四月份分别交水费26元和18元，问四月份比三月份节约用水多少吨？hisarticleincludessomeparts,includin21.设一次函数)0(kbkxy的图象经过A(1,3)、B（0，－2）两点，求此函数的解析式．6四、解答题（本大题共3小题，共32分）hisarticleincludessomeparts,includin22.小明骑单车上学，当他骑了一段路时，想起要买某本书，于是又折回到刚经过的某书店，买到书后继续去学校以下是他本次上学所用的时间与路程的关系示意图(10分)．根据图中提供的信息回答下列问题：（1）小明家到学校的路程是________米（2）小明在书店停留了___________分钟．（3）本次上学途中，小明一共行驶了________米，一共用了______分钟．hisarticleincludessomeparts,includin（4）在整个上学的途中_________（哪个时间段）小明骑车速度最快，最快的速度是___________________米/分．hisarticleincludessomeparts,includin23.已知y是关于x的一次函数，且当3x时，2y；当2x时，3y．(10分)（1）求这个一次函数的表达式；（2）求当3x时，函数y的值；hisarticleincludessomeparts,includin（3）求当2y时，自变量x的值；hisarticleincludessomeparts,includin（4）当1y时，自变量x的取值范围．hisarticleincludessomeparts,includin24.种植草莓大户张华现有22吨草莓等待出售，有两种销售渠道，一是运往省城直接批发7给零售商，二是在本地市场零售，受客观因素影响，张华每天只能采用一种销售渠道，而且草莓必须在10天内售出(含10天)经过调查分析，这两种销售渠道每天销量及每吨所获纯利润见右表：(12分)hisarticleincludessomeparts,includin（1）若一部分草莓运往省城批发给零售商，其余在本地市场零售，请写出销售22吨草莓所获纯利润y（元）与运往省城直接批发零售商的草莓量x（吨）之间的函数关系式；hisarticleincludessomeparts,includin（2）怎样安排这22吨草莓的销售渠道，才使张华所获纯利润最大？并求出最大纯利润．hisarticleincludessomeparts,includin参考答案1.C2.D3.D4.B5.A6.D7.B销售渠道每日销量(吨)每吨所获纯利润(元)省城批发41200本地零售1200088.C9.C10.A11.hisarticleincludessomeparts,includin12.hisarticleincludessomeparts,includin13.2hisarticleincludessomeparts,includin14.hisarticleincludessomeparts,includin15.hisarticleincludessomeparts,includin16.6cm17.；；1818.解：依题意得p点在第四象限，，解得：，即a的取值范围是．hisarticleincludessomeparts,includin19.解：，，hisarticleincludessomeparts,includin、DE垂直于横梁AC，，又D是AB的中点，hisarticleincludessomeparts,includin，hisarticleincludessomeparts,includin答：立柱BC要要2m．hisarticleincludessomeparts,includin20.解：根据图象可知，10吨以内每吨水应缴元9所以元．hisarticleincludessomeparts,includin解法一：由图可得用水10吨内每吨2元，10吨以上每吨元hisarticleincludessomeparts,includin三月份交水费26元元所以用水：吨hisarticleincludessomeparts,includin四月份交水费18元元，所以用水：吨hisarticleincludessomeparts,includin四月份比三月份节约用水：吨解法二：由图可得10吨内每吨2元，当时，知hisarticleincludessomeparts,includin当时，可设y与x的关系为：由图可知，当时，时，可解得hisarticleincludessomeparts,includin与x之间的函数关系式为：，当时，知，有，解得，hisarticleincludessomeparts,includin四月份比三月份节约用水：吨．hisarticleincludessomeparts,includin直接根据图象先求得10吨以内每吨水应缴元，再求小明家的水费；根据图象求得10吨以上每吨3元，3月份交水费26元元，故水费按照超过10吨，每吨3元计算；四月份交水费18元元，故水费按照每吨2元计算，分别计算用水量做差即可求出节约的水量．hisarticleincludessomeparts,includin主要考查了一次函数的实际应用和读图的基本能力解题的关键是能根据函数图象得到函数类型，并根据函数图象上点的实际意义求解．hisarticleincludessomeparts,includin21.解：把、代入得，解得，所以此函数解析式为．hisarticleincludessomeparts,includin1022.1500；4；2700；14；12分钟至14分钟；45023..解：设一次函数的表达式为由题意，得，解得．所以，该一次函数解析式为：；当时，；当时，，解得．当时，，解得hisarticleincludessomeparts,includin24.解：由题意可得，hisarticleincludessomeparts,includin，hisarticleincludessomeparts