1 . 考虑
的非空子集
,满足
中的元素个数等于
中的最小元素,例如,
就满足此条件. 则这样的子集
共有______ 个.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/477aaa8eb4961a77a717ee664fd021ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/765272efc14488ec658fc3302c5e6cc2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
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2 . 记集合
.对任意
,
,记
,对于非空集合
,定义集合
.
(1)当
时,写出集合
;对于
,写出
;
(2)当
时,如果
,求
的最小值;
(3)求证:
.
(注:本题中,
表示有限集合A中的元素的个数.)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a89f895a14b4f202dfe6b19224857c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74c86c0b2a71ee538df6ab1eab3c8b2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd58ba2338450bd94bc2a1ec0a0a51ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/120df58b92e747fc3091f1a3aeff228d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13342dd73eb34ca37aaca5b521706442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19ca324ae5ead82dd03b6cb5afac67a5.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc2d3df37e73a8abea815f37dbb3fff5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cb9ad1e34877b0db02d0219332b0f7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4469a0542c773e329e8cc42e14a84169.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0ca0b9e99203ec575c46cdbf2d4ef0d.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be604061cf1591f7069472269d4c9719.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8839c83b988c42da1fce4a96787583eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c045c7a097a2908732932f4c0c170693.png)
(3)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25376e139f40d0df5ada2c9ebb1da2e4.png)
(注:本题中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c045c7a097a2908732932f4c0c170693.png)
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解题方法
3 . 记
.
(1)若
,求
和
;
(2)若
,求证:对于任意
,都有
,且存在
,使得
.
(3)已知定义在
上
有最小值,求证“
是偶函数”的充要条件是“对于任意正实数
,均有
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d80225e12934cd8d4ffc73d5fad815d.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04beea76c59a6c5b096d8c5a3b77f8a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e1b9f62690647a1597f4000ad5a64b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4c8381377b90826897eb4bf16cb3bae.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28034dcafe542a98d95d4504ad7d8a3e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22dd8b3dc4c609bab82d356a5cc2208d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4def7108b0a2338f07a0143b00b48271.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3761d7ab4d00c91177fdbde67af36089.png)
(3)已知定义在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a43b2faa4f81f32d94612dce724e772b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/625e9d3c298a595678933b59583632c2.png)
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4 . 设集合
为
的非空子集,随机变量X,Y分别表示取到子集
中的最大元素和最小元素的数值.
(1)若
的概率为
,求
;
(2)若
,求
且
的概率;
(3)求随机变量
的均值
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a6a4cff8424ced7841221e2d54d95d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6c4b25a0b76fba785d5769c08714b15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41ab109ec88d6f3d24b2f01ca77e7038.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe08722cf9300fe188dbbb71989c06c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e32a2f594955e456f0fddad1e090bb04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8b3576b4d98a5b4ddc380ddaa0fa281.png)
(3)求随机变量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec9f6ea6346066054b5c722763d6b026.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4f8506fbcb1fae930e1503065b9327a.png)
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5 . 进位制是人们为了计数和运算方便而约定的记数系统,如果约定满二进一,就是二进制:满十进一,就是十进制:满十六进一,就是十六进制.k进制的基数就是k.我们日常生活中最熟悉、最常用的就是十进制.例如,数3721也可以表示为:
一般地,如果k是大于1的整数,那么以k为基数的k进制数可以表示为
.其中
.为了简便,也会把它写成一串数字连写在一起的形式:
,如果不加下标就默认是十进制.
(1)令集合
,将B中的元素按从大到小的顺序排列,则第100个数为多少?
(2)若
,记
为整数n的二进制表达式中0的个数,如
,求
的值.(用数字作答)
(3)十进制中的数999在其他进制中是否也可以表示成一个各位数字之和为27的三位数?如果能,请求出所有的k进制数;如果不能,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8e187d488943587384ba81366d7cb2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bf78d6c2cd4fab5d71e969af0f530e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d47daf899fce1cb06151012a09153d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79224c6579e5f93906b81de9a7f8dbfd.png)
(1)令集合
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b963d591925c79c381bb8c7cf8121390.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39bc26525689d068504cd9298b19d424.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c51592137a3a852f5c802be493e065a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39009f3279d0431b9b444634f18f355b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a80cc2a98cd5e91efa4169a97d4e8e1.png)
(3)十进制中的数999在其他进制中是否也可以表示成一个各位数字之和为27的三位数?如果能,请求出所有的k进制数;如果不能,请说明理由.
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6 . 下列结论正确的是( )
A.若![]() ![]() ![]() |
B.若![]() ![]() ![]() |
C.若![]() ![]() ![]() |
D.若![]() ![]() ![]() |
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7 . 集合论在离散数学中有着非常重要的地位.对于非空集合
和
,定义和集
,用符号
表示和集
内的元素个数.
(1)已知集合
,
,
,若
,求
的值;
(2)记集合
,
,
,
为
中所有元素之和,
,求证:
;
(3)若
与
都是由
个整数构成的集合,且
,证明:若按一定顺序排列,集合
与
中的元素是两个公差相等的等差数列.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88c7a43079a55f6a53b1307b2b04b55e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93cf60f60fedb84bb62a0c00276908ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ce69cd33d105ce280170f0cd0513026.png)
(1)已知集合
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed0081de4e04574dd0884c4e6077fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d651573ff643d295dcceafdb6f1249d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f42500dfa5011086d43ef7e6dac58271.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b27c12cad9040ae9698895e43903747.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(2)记集合
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95c9e547b17582b99e548037172eeff3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41f7f9dc32fa86d097de2b7d78b6b487.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/594e60168219fdebb98b45493de0128a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcc31dcdb99754fc452ff2b92a2fb8c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f093c61867ee4ce75f951d46b9b123.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9dc9ec58912d76aabf278faa7bf06e45.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef96e432405a1037b5aea7514715e52d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa740177330d445b0d506f3b53f9ad2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
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8 . 已知
为实数集的一个非空子集,称
是一个加法群,如果
连同其上的加法运算满足如下四条性质:
①
,
;
②
,
;
③
,
,使得
;
④
,
,使得
.
例如
是一个无限元加法群,
是一个单元素加法群.
(1)令
,
,分别判断
,
是否为加法群,并说明理由;
(2)已知非空集合
,并且
,有
,求证:
是一个加法群;
(3)已知非空集合
,并且
,有
,求证:存在
,使得
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dd242f355d5128425429a83e4b6632c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8362f15e544684164f38ff9ad7c38ac7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ea5a550b5452df9abdbca776c2ff500.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/509a09a7391de2cc86e5e44ccccc981b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8236622218d4d4012d8637538ac9032.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bef35ae51107e991163ea418c8dec53a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebf00e8864c86c3ce8118ea76bf69773.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc118659264aca9e263cb8edc41e9c44.png)
④
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebf00e8864c86c3ce8118ea76bf69773.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71f0119b6de9149150071fe7ed848aa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a065a5ddaa18900ee15a8b436f0fcb95.png)
例如
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/178e8cc61b87b4dc63105ab4fca8680c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7cb4e4e98b375294dc1dccbeebbd6c2.png)
(1)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/809b2e00ab8e43a0f886c7f83846d3d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b113752e4f989a338747b95a40cf386.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d18f9bbb6b9feb166f7ecfb49013262d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64ee969e5c3d880e0209235bb9cfc49f.png)
(2)已知非空集合
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a02a810b3332821bc444f215183c9e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a7d3e3d84e1fdee95574817741d731e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08152bab36dca188978d125e4b7a935a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/489ea5a5f5b5de37e238cbfbb4a01143.png)
(3)已知非空集合
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d28cc3165eef94c22c442b2f30c87cc3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4034552829008c1daaee2701d2afe8dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62e0f9ba8419972cff845bfd91f64297.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93ddc4872d58eaa6bcc432b7b94939f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd5eb4f6f84d264f3403eece1e7c37b7.png)
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9 . 定义1:对于一个数集
,定义一种运算
,对任意
都有
,则称集合
关于运算
是封闭的(例如:自然数集
对于加法运算是封闭的).
定义2:对于一个数集
,若存在一个元素
,使得任意
,满足
,则称
为集合
中的零元,若存在一个元素
,使得任意
,满足
,则称
为集合
中的单位元(例如:0和1分别为自然数集
中的零元和单位元).
定义3:对于一个数集
,如果满足下列关系:
①有零元和单位元;
②关于加、减、乘、除(除数不为0)四种运算都是封闭的;
③对于乘法和加法都满足交换律和结合律,且满足乘法对加法的分配律,则称这个数集
是一个数域.
(1)指出常用数集
中,那些数集可以构成数域(不需要证明);
(2)已知集合
,证明:集合
关于乘法运算是封闭的;
(3)已知集合
,证明:集合
是一个数域.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36e16415b61722f9961e412386e6819f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57e35231b964e293122c4383dac2431b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33bfad095b65beb6e77aee3664b0e6bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36e16415b61722f9961e412386e6819f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cad135b14c9dcd83eab6618d7694c7b0.png)
定义2:对于一个数集
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cc020b0997a2f37b214718112b79d8e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac385ec112e6d61b90d953e3f106ee85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29df165b5fc74dcbc39df74d541148da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb9df3a17aa370eba2add2c13cfc2619.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac385ec112e6d61b90d953e3f106ee85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c4e0c03c5aef711627f1b3124d8b5fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cad135b14c9dcd83eab6618d7694c7b0.png)
定义3:对于一个数集
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
①有零元和单位元;
②关于加、减、乘、除(除数不为0)四种运算都是封闭的;
③对于乘法和加法都满足交换律和结合律,且满足乘法对加法的分配律,则称这个数集
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(1)指出常用数集
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39021e0f386119bd1b5c73b843106e55.png)
(2)已知集合
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37b491b231d0ff8a387813b5686579f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(3)已知集合
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da4c1c450038724991d6d39ecefae405.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
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