1 . 已知
是球
上的三个动点,若三棱锥
体积的最大值为
,则球
的体积为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4278c0911e7df78965e78cff69cac5f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
您最近一年使用:0次
2 . 如图1,在
中,
是
的中位线,沿
将
进行翻折,连接
得到四棱锥
(如图2),点
为
的中点,在翻折过程中,下列结论正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/525cf9256d5dcd7bfc4b555fdcdd7009.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dec2ca6438c82b43f746057d8129885.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8e7cedc39297d66dbb177f2a1f6bee2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
A.直线![]() ![]() |
B.直线![]() ![]() |
C.平面![]() ![]() ![]() |
D.平面![]() ![]() ![]() |
您最近一年使用:0次
解题方法
3 . 在数列
的第
项与第
项之间插入
个1,称为变换
.数列
通过变换
所得数列记为
,数列
通过变换
所得数列记为
,以此类推,数列
通过变换
所得数列记为
(其中
).
(1)已知等比数列
的首项为1,项数为
,其前
项和为
,若
,求数列
的项数;
(2)若数列
的项数为3,
的项数记为
.
①当
时,试用
表示
;
②求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b00f4eb7f1bd2ccefbabf0c1dfa8f69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bcd8ee2d8367c167d6ae0abc741b6b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bcd8ee2d8367c167d6ae0abc741b6b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fd6f81b87ebc6a949329520a6e42ed8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fd6f81b87ebc6a949329520a6e42ed8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bcd8ee2d8367c167d6ae0abc741b6b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b536225194ade4db8e99df253041e034.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/819f6ef3827f73ee7dea7883be3bdfdd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bcd8ee2d8367c167d6ae0abc741b6b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3788785078f4cbc29eb4b3c202d1587.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0704f453b2de48d36911f7db496bbf82.png)
(1)已知等比数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1752474698cd5466dd180df0a00ba9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e5577ef4b9b5764af5e21eef60ebca6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fd6f81b87ebc6a949329520a6e42ed8.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3788785078f4cbc29eb4b3c202d1587.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686ece75006ad358f23314dc8a246e11.png)
①当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0704f453b2de48d36911f7db496bbf82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e9d41db805f5235ec4b69e436690222.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686ece75006ad358f23314dc8a246e11.png)
②求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/147a33b715da5466c2d4f9b18cb925d7.png)
您最近一年使用:0次
解题方法
4 . 若数列
满足
,
的前
项和为
,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e77508401eb0f81e19ef3eb3444240c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
您最近一年使用:0次
解题方法
5 . 函数
与
的图象的交点个数是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74e7e79ac17c51c7a4aaf9d59ec9beb5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21fbd1d0f09fae44dcaf6ace2fdaed0a.png)
A.2 | B.3 | C.4 | D.6 |
您最近一年使用:0次
解题方法
6 . 已知函数
,若
,则
的取值( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/324c31fdada4c31ce6107a2bc21760ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/147f89995c5aa07ce7f797c308c9c7d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/450398974b1561ca801e102e16df6789.png)
A.一定为正 | B.一定为负 | C.一定为零 | D.正、负、零都可能 |
您最近一年使用:0次
7 . 已知集合
,则“
”是“
”的( )条件.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56552cb9c94f329a295d508567103f75.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f665ebe5fc0085518df777174d79410.png)
A.充分不必要 | B.必要不充分 | C.充要 | D.既不充分又不必要 |
您最近一年使用:0次
8 . 如图,一个正八面体的八个面分别标以数字1到8,任意抛掷一次这个正八面体,观察它与地面接触的面上的数字
,得到样本空间
,设事件
为奇数
,事件
,事件
,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/311314491bc52778b4d1c1765894d0ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e171f08a189e8a75094dead09255738f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4ca8bdc812627d925f00ed7c145d696.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94f8529f8e623e55061a44ff5d5050a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a0ace1a8c22a0e1de183642a54a0af5.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
您最近一年使用:0次
9 .
中,若
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abe89e08beb475318e0c7d5a87a8712f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7e4e3219e8964f05b817dbd060c3628.png)
A.54 | B.27 | C.9 | D.![]() |
您最近一年使用:0次
解题方法
10 . 棱长为2的正方体
中,设点
为底面
内(含边界)的动点,则点
到平面
距离之和的最小值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632f2bf1cd0435041fa04b01901d1c8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b04d6165b18f1a031b2a137961832491.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次