1 . 在三棱锥
中,M是线段
的中点,
,
,
,
.
(1)证明:P在平面
内的射影O为
的垂心;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb3735a467f788624fe63946e0da5b6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59fe75f967e8915c9124a5d4ac420a4e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c327b3e91d8bea53255d9308a952a276.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/827c7d9ca8f0e06a09bd37e930b3c3ee.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/29/d44cbe49-473b-42e9-a1e4-0a171e6be968.png?resizew=156)
(1)证明:P在平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b796bbaeb8450404c2d146283562006e.png)
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解题方法
2 . 如图,在平面直角坐标系
中,点
,直线
,设圆C的半径为1,圆心在l上.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/29/5426adc8-1854-4d34-b385-3a24824b222a.png?resizew=147)
(1)若圆心C也在直线
上,过点A作圆C的切线,求切线的方程;
(2)若圆C上存在点M,使
,求圆心C的横坐标a的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ee31829d0d4d5f779a957d7df8058ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc878a5fd7b508cf817cbb65d3940547.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6db0a1cbf7b0ed76c443b953af8734d0.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/29/5426adc8-1854-4d34-b385-3a24824b222a.png?resizew=147)
(1)若圆心C也在直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b8c1212804e6d784756d48083d166e8.png)
(2)若圆C上存在点M,使
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a464b0c729f294287d3d89119a585293.png)
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解题方法
3 . 已知双曲线
(
,
),实轴长为8,虚半轴长为
,
,
分别为双曲线左右焦点,点
,P为双曲线在第一象限上任意一点,则下列说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f3fa0b40fb0d9b8c62e37316ab3b04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94440d3e4c073f94f2b266ff99d50e74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67ca5fd57c2c2fcc3c7a574fdd1467d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38387ba1cadfd3dfc4dea4ca9f613cea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5076289823db419f94e9c0c8f4aafd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3fb78c5f885034612c0e030b920143d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b17a80dee44d744cf9ce671d4e8c0948.png)
A.![]() |
B.![]() |
C.若直线l交双曲线于A,B两点,且Q为![]() ![]() |
D.![]() ![]() |
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解题方法
4 . 下列说法不正确的有( )
A.若两条直线![]() ![]() ![]() |
B.若直线![]() ![]() |
C.过点![]() ![]() |
D.已知直线![]() ![]() ![]() ![]() ![]() |
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解题方法
5 . 已知椭圆
的离心率为
,
,
,
,
,设P为椭圆C上一点
的面积的最大值为
.
(1)求椭圆C的方程;
(2)当P在第三象限,直线
与y轴交于点M,直线
与x轴交于点N,求证:四边形
的面积为定值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad523e69a1bf925e73a22900b9855df2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5989c84e320b504511f23eeb6e7357.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3160fc73f2a90ae4a1a97351ab2673b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9199b50dd0036be9b764c621d1d46f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a87e24ea042ecf3f25150338e22b45b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea1a9821a00b71f6b7d7a76d91b3f810.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9374cdec65a41dc616f6f099551880d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e2031d209711b058f3d278ede3c1d33.png)
(1)求椭圆C的方程;
(2)当P在第三象限,直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e53abbd672b82a02c4975f99fbbd2c37.png)
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解题方法
6 . 已知数列
的前n项和为
,且
,
.
(1)求数列
的通项公式;
(2)在
与
之间插入n个数,使这
个数组成一个公差为
的等差数列,在数列
中是否存在3项
,
,
(其中
成等差数列)成等比数列?若存在,求出这样的3项,若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/beb08c935c5a6dae2b2e53cfa8eac740.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/090426eb29836bc30c006b3739c08057.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3468a665ac713ab7b400c672f19650a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82e260b088f071983f254ce8f5163fcd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b783cf91e34e692ce8e171f0965cb53f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee8598379ec01edc16c72c1d3fa3ce81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8904e7018ec79c8b0efdcb3ba67cb7cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2554efe1860dc6c769c34d8cfa6de3e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7955013519718c9ac993531062495e95.png)
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解题方法
7 . 甲、乙两人组成“上元队”参加猜灯谜比赛,每轮活动由甲、乙各猜一个灯谜,已知甲每轮猜对的概率为
,乙每轮猜对的概率为
.在每轮活动中,甲和乙猜对与否互不影响,各轮结果也互不影响.记事件
“甲第一轮猜对”,
“乙第一轮猜对”,
“甲第二轮猜对”,
“乙第二轮猜对”.
(1)求“上元队”在第一轮活动中仅猜对1个灯谜的概率;
(2)求“上元队”在两轮活动中,甲、乙猜对灯谜的个数相等且至少为1的概率.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf31876698721a199c7c53c6b320aa86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5f1e5d29de6e4d72bfed62d9c14dde5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1f9fabbbe61a759e52ec975215e2e7c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26308ea6d8f321d27acbd7f9b131f9f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a6d85799453899836bc34ad276ec80e.png)
(1)求“上元队”在第一轮活动中仅猜对1个灯谜的概率;
(2)求“上元队”在两轮活动中,甲、乙猜对灯谜的个数相等且至少为1的概率.
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8 . 若恰有三组不全为0的实数对
满足关系式
,则实数t的所有可能取值的和为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30277e0be448b4955903e81e8795e45d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fed30b52ac93e8a4679b803c893a5d93.png)
您最近一年使用:0次
9 . 已知
是等比数列,且
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dbd9ff686703cad03aa383e5fec21.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb334e165679c6cb500c994cffa47147.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ff6de1ee895470114429ac01726f405.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dbd9ff686703cad03aa383e5fec21.png)
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10 . 设数列
的前n项和为
,
,则下列说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9ba984e922424ae65819c8a2bc27c64.png)
A.![]() |
B.当且仅当![]() ![]() |
C.![]() |
D.![]() ![]() ![]() ![]() ![]() ![]() ![]() |
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