1 .
表示数列
的前
项积,如
.已知
,则下列结论正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df9c6801661fb72d3bb24771bd258b03.png)
![](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/dc6ccf4fc5fe2eafc7a8ccb52b45ef0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0065e684138127b340c7ac3ec7f060f.png)
A.![]() | B.![]() |
C.![]() | D.满足![]() ![]() |
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解题方法
2 . 已知
,随机变量
的分布列为
设
,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a957fa02ba144b3aa1a26133411151d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![]() | 4 | 6 | 8 |
![]() | ![]() | ![]() | ![]() |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec473812bc2849d0bdf60a9f861a6fa7.png)
A.数列![]() | B.数列![]() |
C.数列![]() | D.数列![]() |
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3 . 设
为
的导函数,若
在
上恒成立,且
在
上不恒成立,则
在
上单调递增;若
在
上恒成立,且
在
上不恒成立,则
在
上单调递减.若
在
上单调递增,则称
为
上的凹函数;若
在
上单调递减,则称
为
上的凸函数.
(1)判断函数
在
上的凹凸性,并说明理由;
(2)若函数
为
上的凹函数,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/724340d69477c0ec2418c392b22b1cab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17562636810999b1c98c5e99b5c3e0dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/868a4cf0549507ca5f2a18b2d1070085.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f3f07066c570810d821b3ed430d233d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/868a4cf0549507ca5f2a18b2d1070085.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/724340d69477c0ec2418c392b22b1cab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/724340d69477c0ec2418c392b22b1cab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
(1)判断函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16bf2342bfb8555b9fdde6209a6cf30a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7160d93f92089ef36f3dab809d3114b8.png)
(2)若函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6f77c262f0c09a6d617d5a50020467c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a43b2faa4f81f32d94612dce724e772b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
您最近一年使用:0次
4 .
中,
,点
在线段
上,下列结论正确的是()
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b375f88294490a62f58d7070be962ef5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
A.若![]() ![]() | B.若![]() ![]() |
C.若![]() ![]() | D.若![]() ![]() ![]() |
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解题方法
5 . 如图,在多面体
中,
平面
,四边形
是正方形,
.
与平面
所成角的余弦值;
(2)证明:
平面
;
(3)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9bf53e97203aa720fe3a09b9bf534af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe240da6d51d3efea02af13e73b87ab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a9fd76d8997e3b2db7d9cb9b72d0f80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2e30e6cd7e777ccd3edb50a9bd3163c.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db807b09cc550f476b3f8fa0c6a14425.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
(3)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4ca19321c6776be24e4be5033b60ed7.png)
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6 . 在
中,内角A,B,C的对边分别为a,b,c,且
.
(1)求角B;
(2)若
为锐角三角形,
,D是线段AC的中点,求BD的长的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f7cd8020fdf7ae5a64bc25d89293782.png)
(1)求角B;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
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解题方法
7 . 如图,在钝角△ABC中,角A,B,C所对的边分别是a,b,c,
,过点A作与
垂直的单位向量
,将
与向量表达式
两边进行数量积的运算,即
,化简后得到的结论是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0b11d338fa58dde72c8a7402db3b97d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af5f1b06a56fc382feed28e01f1ad102.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2980a18e4d0a2a795b7983a1a1866db7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2980a18e4d0a2a795b7983a1a1866db7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0f5f98dd9945ceca75a66c207f4915a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c16be36e0f83927ac833777db5aa0fad.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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解题方法
8 . 定义:
.已知a,b,c分别为△ABC的三个内角A,B,C所对的边,若![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c23f242dc06d519ed1529c93bd1ec75e.png)
,且
,则边c的最小值为____________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0c8894e0b37af5da23a1c1bffb32017.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c23f242dc06d519ed1529c93bd1ec75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/771df37a312dac1fb332a31a10340c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ff7e62312dbd1cd5b50a6dc7fdfc166.png)
您最近一年使用:0次
解题方法
9 . 已知
,
.
(1)求
与
的夹角的余弦值;
(2)若
,求
值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5463fb0b7d03747aa4d680620ca81be2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80e97ecaf990a636c4648956663ff6b0.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed492f7b29166ba5c1f0023b05a439c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3143307ad0ba4a631eac04e814993655.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/352bab087decd04caacfe66a9c0d972b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
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10 . 已知向量
,
,若
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81f4dcf415977dea53f52a85b6b82136.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/991a4493cfd34d25c6ffbadc12c27978.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c98b14b10c0acef3c3d783984f4bb25.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
A.5 | B.2 | C.3 | D.4 |
您最近一年使用:0次