2018—2019学年福安一中第一学期期中考高一数学试卷(满分:150分; 时间:120分钟)注意事项：1.答卷前，考生务必将班级、姓名、座号填写清楚。

2.每小题选出答案后，填入答案卷中。

3.考试结束，考生只将答案卷交回，试卷自己保留。

第I 卷（选择题 共60分）一、选择题：本小题共12小题，每小题5分，共60分．在每小题给出的四个选项中，只有一项是符合题目要求的．1．已知集合{}.6,5,4,3,2,1=I {}6,2,1=M ，{}4,3,2=N . 则集合{}6,1= A ．MNB ．M NC ．()I MN ðD ．()I NM ð2．函数()1lg(1)f x x x =-+的定义域是 A ．),1(+∞- B ．(1,1)- C. (]-11，D ．)1,(--∞3．下列各组函数中，表示同一函数的是A. 2(),f x x =3()g x x =B. 2(),f x x =2()()g x x =C. 2(),x f x x =()g x x = D ．,0(),(),0x x f x x g x x x ≥⎧==⎨-<⎩4．已知函数21,0(),0xx f x x x ⎧+≥⎪=⎨<⎪⎩, 若()3,f x = 则实数x 的值为A ．3-B ．1C ．3-或1D ． 3-或1或35．下列函数是奇函数且在(0,)+∞上单调递减的是A.2y x =- B.y x = C.12log y x = D. 1y x=6．函数()327x f x x =+-的零点所在的区间为A. (0,1)B. (1,2)C. (2,3)D. (3,4) 7．三个数0.63,a = 3log 0.6,b = 30.6c =的大小顺序是A ．a >c >bB ．a >b >cC ．b >a >cD ．c >a >b 8．函数()x f x a =与1g()log ax x =（01a a >≠且）在同一坐标系中的图象可以是xy11oxy11oxy-111o9．已知定义在R 上的函数()f x 满足:()()()1f x y f x f y +=++，若(8)7f =, 则(2)f = A. 7 B. 3 C. 2 D. 110．双“十一”要到了，某商品原价为a 元，商家在节前先连续5次对该商品进行提价且每 次提价10%.然后在双“十一”期间连续5次对该商品进行降价且每次降价10%.则最后该 商品的价格与原来的价格相比A ．相等B ．略有提高C ．略有降低D ．无法确定 11．已知()f x 是定义域为[]3,3-的奇函数, 当30x -≤≤时, 2()2f x x x =-，那么不等式 (1)(32)f x f x +>-的解集是 A. []0,2 B. 20,3⎡⎫⎪⎢⎣⎭ C. 2(,)3-∞ D. 2(,)3+∞ 12．已知方程1ln 0xx e ⎛⎫-= ⎪⎝⎭的两根为12,x x ，且12x x >，则A ．11211x x x << B. 21211x x x << C. 11211x x x << D. 21211x x x <<第II 卷 （非选择题共90分）二、填空题：本大题共4小题，每小题5分，共20分．把答案填在答题卡相应位置． 13．幂函数()f x x α=的图像过点(2,2)，则(16)f = ．14．函数213()log (9)f x x =-的单调递减区间为 ．15．设实数,y x 满足：1832==y x ，则=+yx 21_________.16．给出下列说法①函数()11f x x x =++-为偶函数；②函数13xy ⎛⎫= ⎪⎝⎭与3log y x =-是互为反函数；③ 函数lg y x =在(,0)-∞上单调递减；A.B.C.D.yx65-6-5-4-3-1-2-665432O-5-4-3-2-143211④函数1()(0)12xf x x =≠-的值域为(1,)+∞. 其中所有正确的序号是___________ .三、解答题：本大题共6小题，共70分．解答应写出文字说明、证明过程或演算步骤． 17．（本小题满分10分）求下列各式的值：（Ⅰ）+1022(21)21-+；（Ⅱ）2l o g 32l g 12.5l g 8l o g 82++- . 18．（本小题满分12分）已知全集U =R ，集合}31|{≤≤=x x A ，集合}42|{>=x x B . （Ⅰ）求 ()U B A ð；（Ⅱ）若集合{}1C x a x a =<<+，且C A C =, 求实数a 的取值范围.19． (本小题满分12分)已知()f x 是定义在R 上的偶函数，当0x ≥时，21,02()515,2x x f x x x ⎧+≤<=⎨-+≥⎩（Ⅰ）在给定的坐标系中画出函数()f x 在R上的图像（不用列表）；（Ⅱ）直接写出当0x <时()f x 的解析式； （Ⅲ）讨论直线()y m m =∈R 与()y f x =的图象 的交点个数． 20．(本小题满分12分)已知定义在R 上的函数3()13xxb f x a -=+⋅是奇函数.（Ⅰ）求实数,a b 的值；（Ⅱ）判断()f x 的单调性，并用定义证明.21．(本小题满分12分)水葫芦原产于巴西，1901年作为观赏植物引入中国. 现在南方一些水域水葫芦已泛滥成灾严重影响航道安全和水生动物生长. 某科研团队在某水域放入一定量水葫芦进行研究，发现其蔓延速度越来越快，经过2个月其覆盖面积为218m ，经过3个月其覆盖面积为227m . 现水葫芦覆盖面积y （单位2m ）与经过时间(x x ∈N)个月的关系有两个函数模型(0,1)x y ka k a =>>与12(0)y px q p =+>可供选择.23 1.732,lg 20.3010,lg 30.4771≈≈≈≈ ） （Ⅰ）试判断哪个函数模型更合适，并求出该模型的解析式；（Ⅱ）求原先投放的水葫芦的面积并求约经过几个月该水域中水葫芦面积是当初投放的1000倍. 22．（本小题满分12分） 已知函数2()log (21)xf x kx =+-的图象过点25(2,log )2. （Ⅰ）求实数k 的值; （Ⅱ）若不等式1()02f x x a +->恒成立，求实数a 的取值范围； （Ⅲ）若函数1()2()241f x xx h x m +=+⋅-，2[0,log 3]x ∈，是否存在实数0m <使得()h x 的最小值为12，若存在请求出m 的值；若不存在，请说明理由.高一数学试卷答案与评分标准一.选择题：13. 4 14.3+∞（，）15.1 16. ①②③ 三、解答题：本大题共6小题，共70分．解答应写出文字说明、证明过程或演算步骤． 17．（本小题满分10分） 解：（Ⅰ）原式=22-2()()212121-+-·············································· 4分=22-+2+21+1 =2 ·············································································· 5分（Ⅱ）原式=322lg12.58log 23⨯+- ································································ 8分=3lg10032+- =2-32·························································································· 9分=12 ····························································································· 10分18．（本小题满分12分）解：（Ⅰ）24x > 2x ∴>()2,B ∴=+∞ ·············································································· 2分 (],2u B ∴=-∞ð ············································································· 4分 ()(],3u B A ∴=-∞ð ··················································································· 6分（Ⅱ）C A C = C A ∴⊆ ······························································································ 7分 113a a ≥⎧∴⎨+≤⎩ ······························································································ 11分 12a ∴≤≤ ······························································································· 12分 （有讨论C=∅的情况，过程正确，不扣分） 19． (本小题满分12分) 1（Ⅰ）解：函数图象如图：·············································································································· 4分（Ⅱ）21,20()515,2x x f x x x ⎧+-<<=⎨+≤-⎩ ··························································· 6分（Ⅲ）设交点个数为()g m 当5m >时，()0g m =； 当5m =时，()2g m =； 当15m <<时，()4g m =； 当1m =时，()3g m =； 当1m <时，()2g m =；……………………………………………………..12分综上所述，0,52,1()3,14.15m m g m m m >⎧⎪<⎪=⎨=⎪⎪<<⎩或m=5(没有写出分段形式答案不扣分) 20.（I ）3()13x xb f x a -=+⋅是定义在R 上的奇函数(0)0f ∴=即003013b a -=+⋅ ············································································ 1分 得1b = ··································································································· 2分1121323(1)113313f a aa ----===+⋅++⋅11132(1)1313f a a --==+⋅+ 由(1)(1)f f -=-得1a = ··············································································· 3分经检验：1,1a b ∴==时，13()13x xf x -=+是定义在R 上的奇函数····························· 4分1,1a b ∴== ····························································································· 5分解法二：3()13x xb f x a -=+⋅331()133x x xxb b f x a a---⋅-∴-==+⋅+ ···································· 1分由()()f x f x -=-得313313x x x xb b aa ⋅--=-++⋅ ························································· 3分1a ∴=, 1b =···························································································· 5分（II ）()f x 在R 上单调递减. ······································································· 6分 证明如下： 由（I ）知13()13x xf x -=+设12,x x 是R 上的任意两个实数，且12x x <， ···················································· 7分 则1212122112121313()()1313(13)(13)(13)(13)(13)(13)x x x x x x x x x x f x f x ---=-++-+--+=++21122(33)(13)(13)x x x x -=++ ······················································································· 10分 21121212330,(13)(13)0()()0x x x x x x f x f x <∴->++>∴->即12()()f x f x >()f x ∴在R 上单调递减. ······················································· 12分解法二：132()11313x x xf x -==-+++ ································································· 6分 ()f x 在R 上单调递减. ··············································································· 7分 设12,x x 是R 上的任意两个实数，且12x x <，则 ················································· 8分 12121222()()(1)(1)1313221313x x x x f x f x -=-+--+++=-++21122(33)(13)(13)x x x x -=++ ····················································································· 10分 21121212330,(13)(13)0()()0x x x x x x f x f x <∴->++>∴->即12()()f x f x >()f x ∴在R 上单调递减. ······················································· 12分 21．(本小题满分12分) 解：(0,1)xy ka k a =>>的增长速度越来越快，12(0)y px q p =+>的增长速度越来越慢.(0,1)x y ka k a ∴=>>依题意应选函数 ······················································· 2分则有23=18=27ka ka ⎧⎪⎨⎪⎩， ·················································································· 4分解得3=2=8a k ⎧⎪⎨⎪⎩38()()2x y x N ∴=∈， ··············································································· 6分 （Ⅱ）当0x =时，8y = ············································································ 7分 该经过x 个月该水域中水葫芦面积是当初投放的1000倍. 有38()810002x ⋅=⨯ ····················································································· 9分 32log 1000x ∴=lg10003lg 2=······························································································· 10分 3lg3lg 2=-17.03≈ ·································································································· 11分 答：原先投放的水葫芦的面积为8m 2, 约经过17个月该水域中水葫芦面积是当初投放的1000倍.············································································································· 12分 22．（本小题满分12分）（I ）函数2()log (21)x f x kx =+-的图象过点25(2,log )22225log (21)2log 2k ∴+-= 12k ∴=···································································································· 2分 （II ）由（I ）知21()log (21)2x f x x =+-1()()02g x f x x a ∴=+->恒成立即2log (21)0x a +->恒成立令2()log (21)x u x =+，则命题等价于min ()a u x < 而2()log (21)x u x =+单调递增 2()log 1u x ∴>即()0u x >0a ∴≤ ··································································································· 6分 （III ）21()log (21)2x f x x =+-，21()log (21)2()2412412141xf x xx x x x h x m m m ++∴=+⋅-=+⋅-=++⋅-2(2)2x x m =+ ························································································ 7分 令22,[0,log 3],[1,3]x t x t =∈∴∈2,[1,3]y m t t t ∴=⋅+∈ 当0m <时，对称轴12t m=- ①当122t m =->，即104m -<<时 min 1(1)12y y m ==+=12m ∴=-，不符舍去. ················································································ 9分 ②当122t m =-≤时,即14m ≤-时 min 1(3)932y y m ==+= 51184m ∴=-<- 符合题意. ········································································ 11分综上所述：518m =- ·················································································· 12分。