数学模拟试卷(二)答案.docVIP

数学试卷综合（二） 参考答案 一、选择题（本大题共10小题，每小题4分，共40分）． 题号 1 2 3 4 5 6 7 8 9 10 答案 D B C B B D C A D A 二、 5小题，每小题4分，共20分）． 11．??? 12．（或答） 　13． －1　? 14．　?? 15．0 三、（本大题共3小题，每小题8分，共24分）． 16．解：此题答案不唯一，只要在方格内添的二个正方形使整个图形是对称图形就给分，每答对一个给4分，共8分．? ? ? ? ? ? ?  17．解：设正方形的边长为，圆的半径为R， 则， ．······························································································· 2分 ∴，．···················································································· 4分 ∴　，．···················································· 6分 ∵　，∴ ． ······················································································· 8分 ?18．解：（1）由题意得 ，? ······································································· 2分 即．　····································································································· 3分 ∴．　 ············································································································ 4分 （2）由（1）知当时，．··························································· 6分 ∴取得黄球的概率 ．·························································· 8分 19． 解：（1）由两个统计图可知该校报名总人数是（人）．············· 2分 （2）选羽毛球的人数是（人）．? ····················································· 3分 因为选排球的人数是100人，所以， ························································ 4分 因为选篮球的人数是40人，所以， 即选排球、篮球的人数占报名的总人数分别是25%和10%．·········································· 5分 （3）如图（每补充完整一个得1分，共3分）．···························································· 8分 ? 20．解：令，即，当方程有两个不相等的实数根时，该函数的图象与x轴有两个交点． 　??? 1分 此时即．····························································································· 2分 由已知　，······························································································ 3分 ∵　，　　 ∴　，················································································ 4分 ∴　　， ∴　，　∴(舍去)．····································································· 6分 当时，，　解得．···························· 7分 综上：，为所求．　················································· 8分 ??????