名校
1 . 有以下结论:
①不存在
,使得
;
②若
,则a,x,b成等比数列;
③设O是平面ABC内一定点,P为平面ABC内一动点,若
,则O为
的外心;
④已知
所在的平面上的点P满足
,则直线AP一定经过
的内心.
其中正确的结论序号为______ (请把所有正确的结论序号都写出来).
①不存在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e36c9c91220b0f2cbd4a48e8fa90e3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69b682778d7f3b4bb6e0950de69453c3.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99047070ae53baae5a237f7fc510db89.png)
③设O是平面ABC内一定点,P为平面ABC内一动点,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af1983fa9be423eecc616de136bb1d35.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
④已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8908bb969d28eb473a60c9e8f4073e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
其中正确的结论序号为
您最近一年使用:0次
名校
解题方法
2 . 给出以下几个结论:
①若等比数列
前n项和为
,
,则实数
;
②若数列
,
的通项公式分别
,
,且
,对任意
恒成立,则实数a的取值范围是
;
③设在
中,内角A、B、C的对边分别为a、b、c,且
,则
的最大值为
;
④在
中,三内角A,B,C所对的边分别为a,b,c,则
;
其中正确结论的序号为______ .
①若等比数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97b794ed9de8e93de6e067c3d0259558.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e145b6046bc80d0ffecc61ac67c87ca1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b108ab31cc093f03cf48ad65429889e.png)
②若数列
![](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/20ae956b7c89f63fcb27a507c9728344.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6dc7eb66f5d777c283a395eda5635d4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83ac679ad239090a6ce21a10b47e332c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e145b6046bc80d0ffecc61ac67c87ca1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54c30f7465c99d88caf6703bc7365a51.png)
③设在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1f32fe2cea6b046da549c0d04e103e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afd0b09f2c1c75840f0a1a1eb3528ae3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/827ccf0c04aa941ba20d5f4c6068b46b.png)
④在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d22b0c674439368ca4d402fe8ce0888.png)
其中正确结论的序号为
您最近一年使用:0次
3 . 已知
为数列
的前
项和,且
,
(
).给出下列3个结论:①数列
一定是等比数列;②若
,则
;③若
,
,
成等比数列,则
.其中,所有正确结论的序号为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f17a7b5a8970e7e8da883b2e93d3698.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7fab51121848ce166035ceab6f4e00b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10bbdef421c976962a270a2beabbad91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc6409c388f766ff05be0e5d080bed2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8a1d093160d34fe50bbcedff8f5bc12.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/001d1773df6520fba1d44007fe942836.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5da4cd81500bdb43118150dbdb1541e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc858b7a95c5006a44067022da09f667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b9f0255df77526718a46c4e78b78513.png)
A.② | B.②③ | C.①③ | D.①②③ |
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4 . 判断正误,正确的写正确,错误的写错误.
(1)等比数列中不存在数值为0的项.( )
(2)常数列a,a,a,a,…一定是等比数列.( )
(3)若数列
的通项公式是
,则
一定是等比数列.( )
(4)存在一个数列既是等差数列,又是等比数列.( )
(5)任何两个实数都有等比中项.( )
(6)数列
是等比数列.( )
(7)若一个数列从第2项起每一项与前一项的比为常数,则该数列为等比数列.( )
(8)等比数列的首项不能为零,但公比可以为零.( )
(9)常数列一定为等比数列.( )
(1)等比数列中不存在数值为0的项.
(2)常数列a,a,a,a,…一定是等比数列.
(3)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4c3b457d892036cbdc51b8e4517112b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
(4)存在一个数列既是等差数列,又是等比数列.
(5)任何两个实数都有等比中项.
(6)数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a098083ab2dfdcbcee43c1b4cc876fba.png)
(7)若一个数列从第2项起每一项与前一项的比为常数,则该数列为等比数列.
(8)等比数列的首项不能为零,但公比可以为零.
(9)常数列一定为等比数列.
您最近一年使用:0次
5 . 判断正误(正确的写正确,错误的写错误)
(1)若一个数列从第二项起每一项与前一项的比为常数,则该数列为等比数列.( )
(2)等比数列的首项不能为零,但公比可以为零.( )
(3)常数列一定为等比数列.( )
(4)任何两个数都有等比中项.( )
(1)若一个数列从第二项起每一项与前一项的比为常数,则该数列为等比数列.
(2)等比数列的首项不能为零,但公比可以为零.
(3)常数列一定为等比数列.
(4)任何两个数都有等比中项.
您最近一年使用:0次