解题方法
1 . 已知向量
,
,若
,
的夹角为钝角,则
的取值范围是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/303e0f7b92a9fb0bca726e1de9d9df98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d830f1864615e29ce030b533bed3834.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a2f4b1178f68bd147d1a2a6acd04435.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b45ba716f03748c19b7ce2f99af536ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
您最近一年使用:0次
2 . 已知数据
的平均数为10,方差为5,数据
的平均数为
,方差为
,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2ef7e4d476f582e5c48c40bfb95d59f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10be67b56c6c8299d1433c473df384b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfbe7f95b5d89f9409ec24536da9e826.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/671f43c79d612c93a6d160335e86e177.png)
A.![]() ![]() | B.![]() ![]() |
C.![]() ![]() | D.![]() ![]() |
您最近一年使用:0次
3 . 设复数
(i为虚数单位),则下列结论正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54b91cd2f82cadbdeae3a6518ec5a06c.png)
A.![]() ![]() | B.![]() |
C.![]() | D.![]() |
您最近一年使用:0次
解题方法
4 . 如图,四棱锥
中,
面
,四边形
为正方形,
,
与平面
所成角的大小为
,且
,则四棱锥
的外接球表面积为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00bab2c27eac56fffa4cd7dbe1dcdf1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5b87e9c2668babc037844dd615cb7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
A.26π | B.28π |
C.34π | D.14π |
您最近一年使用:0次
5 . 已知m,n为两条不同的直线,α,β为两个不同的平面,则下列结论中正确的是( )
A.若![]() ![]() ![]() |
B.若m⊥α,n⊥α,则![]() |
C.若![]() ![]() ![]() ![]() ![]() |
D.若α⊥β,![]() |
您最近一年使用:0次
6 . 一只不透明的口袋中装有形状、大小都相同的6个小球,其中2个白球,1个红球和3个黄球,从中1次随机摸出2个球,则恰有一球是黄球的概率是_______ .
您最近一年使用:0次
7 . 已知
,
,若
,则实数
的值( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db10355e559fda75bd2f8f47278ec8ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9c8e6f7d2099684b9e4da51907e424f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33608c167be83dd4e9b2447885ed85cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
A.![]() | B.3 | C.2 | D.![]() |
您最近一年使用:0次
8 . 已知数列
是公比为2的等比数列,数列
是等差数列,
,
,
.
(1)求数列
,
的通项公式;
(2)设
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ed1b0d16948c3afaa12adf30e839151.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65a4446af2614adaa44589dfcb8de156.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fffc1532361e0dcbd663ef8a8faf08c1.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d44ddab6e0c60119be69985ae7fa65b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
您最近一年使用:0次
9 . 已知数列
中,
,则
于( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3bad85fca280cee855545e84fba867b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5da4cd81500bdb43118150dbdb1541e6.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
10 . 记
内角
的对边分别为
,
,
,已知
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f23d9f62826855e3caf26d7d4640c1c.png)
(1)求
;
(2)若
,求
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac1143aa4477719481003ec4cc75a565.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f23d9f62826855e3caf26d7d4640c1c.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7bd466d65409c10c1a1ce60a3c5ea1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
您最近一年使用:0次