江苏省徐州市市区2021-2022学年九年级+数学一模检测+

这是一份江苏省徐州市市区2021-2022学年九年级+数学一模检测+，文件包含江苏省徐州市2021-2022学年九年级第二学期数学一模检测pdf、九年级数学答案及评分标准docx等2份试卷配套教学资源，其中试卷共10页， 欢迎下载使用。
2021—2022学年度第二学期一模检测九年级数学（答案及评分标准）一、选择题(每题3分，共24分)题号12345678答案ACABCCDB   二、选择题 (每题3分，共30分)9.  ；         10. ；        11. ；    12 .2；          13. 24π；14. ；   15. ；     16.72°；         17. ；      18. 三、解答题 (共86分)19.（1）原式=-1++2·························································4分=2+1. ··························································5分   （2）原式=······························································3分            = - 1··························································5分20.(1)解：··································································2分          x - 7＝0或x + 1＝0························································3分          x1 =7 ，x2 = -1  ·························································5分(2) 解不等式①得，，······················································2分解不等式①得，························································4分所以不等式组的解集是··················································5分21. (1)  120；条形图高12（图略）···················································2分(2)  72°·······························································4分(3) ···································································6分答：对“在线讲授”最感兴趣的学生人数是780人································7分22. 解：（1）∵四边形ABCD是平行四边形，∴，AD∥BC,·····························1分∴ ,······································································2分∵DE⊥AB, CF⊥AB,∴········································································3分∴△ADE≌△BCF····························································4分（2）∵，∴DE∥CF,·························································5分∵四边形ABCD是平行四边形，∴DC∥AB,··········································6分∴四边形DEFC是平行四边形,···················································7分∵∴四边形DEFC是矩形·······················································8分23. 解：（1）；·······························································2分（2）树状图（略）；.························································5分共有6种等可能情况，其中是A、C的有2种情况，则抽到恰好是A、C的概率是···················································7分24.解：设原计划完成第二期建设需要x年.············································1分根据题意，得：， ···························································4分解得：x＝5································································6分经检验x＝5是原方程的解······················································7分答：设原计划完成第二期建设需要5年.············································8分25. 解：点坐标为·······························································2分（2）∵一次函数的图象与坐标轴交于，两点，∴点······································································3分∵点为线段的中点，∴点······································································5分∴点和点平移后的对应点坐标分别为，···········································6分∴,   ∴····································································8分26. (1)证明：连接OC∵点C在圆上，OB=2，∴OC=OB=2··············································1分∵OA＝6，AC＝，∴,∴·······································································3分∴,∴AC是⊙O的切线．······················································4分                                                       (2)过点O作BC的垂线垂足为D∵BC∥OA, ∴∵, ∴△ODC∽△OCA,∴∴,······················································6分∴S=·····································································8分27.（1）作图(略)······························································2分（2）①解：过点F作DE的垂线，垂足为H∵AC=，∴BC=6,∵DC=t，∴BD=6 –t, ·························································1分∵DE∥AC，△DEF是等边三角形，∴，在RT△DFC中，,····························································2分在RT△DBE中，,····························································3分∵2FC=DE，∴，∴t=2 .·······················································4分②当CD=CF时,  过点C作DF的垂线，垂足为M ，在RT△DMC中，∴DM=2DF=2DE，∴，∴t=·····················································6分   当CD=DF时   ，∴·······································································8分当CD=DF时过点F作DC的垂线，垂足为N ，∴在RT△DFN中，∵DF=DE，∴，∴t=3. ··························································10分      28. 解：（1）过点D作OF的垂线，垂足为H∵BF⊥y轴，∴BF∥DH∥AO, ∴，············································1分∵OF=4，∴OH=2，∵OC=3，∴ CH=OC-OH=1∵DH⊥EC，∴CE=2CH=2·····················································2分（2）连接AC、BC∵OA=OC，，∴∵AB是⊙D的直径，∴，∴，∴BF=CF=FO -CO=1,∴点B的坐标是（-1，-4）·····················································4分将A (－3，0)、B (－1，－4)、   C (0，－3)代入得               ． ∴ ∴y=x2+2x-3．·····························································6分（3）∵设存在点P，∴BP=m+4，过点P作x轴的垂线,垂足为H，,∵AH=2，BH=4, ∴AB=,∵⊙P与直线AB和x轴都相切,∴,即∴，∴存在P，.····························································10分