名校
1 . 已知关于
,
的方程组
其中
.
(1)当
时,求该方程组的解;
(2)证明:无论
为何值,该方程组总有两组不同的解;
(3)记该方程组的两组不同的解分别为
和
,判断
是否为定值.若为定值,请求出该值;若不是定值,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1685feba617e3d56860fe0a3a59804f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c36b234ba460321e811de1729eadd4b6.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5095a28bb1b91bf6bed9e2cfbd76bb18.png)
(2)证明:无论
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
(3)记该方程组的两组不同的解分别为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3396ead2a01ebd1d6134732541008a7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/734a03b0e1c4de970668548ebb944fc0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0af05cf4260c845bfb0675073bd81b6.png)
您最近一年使用:0次
2023-11-14更新
|
146次组卷
|
2卷引用:北京市西城区北京师范大学附属实验中学2023-2024学年高一上学期期中测验数学试题
名校
2 . 已知实数x,y满足方程
.
(1)求
的值;
(2)设
与
是方程组
两组不同的解,其中
.求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1beb6812158ca2a3082bd13ca07578f0.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c1afbc87ccffbc98b9ab58df8c69bee.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99307ab4373fbe72422ae5aa980db61c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41039d45e37899d233232de3d802b105.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccee8eb181dc117834582bc433eca559.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aab3cf6695638d5bcd26580174d7cbf7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1da3ff6f17be99ec311610efa08ba002.png)
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3 . 已知方程组
的解集为
.
(1)若方程组的一个解为
,求
的值;
(2)若
时,求
;
(3)当
时,
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb834a8b167f55c254e20d8f1a698be3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf04b4991cc8ef8ffb9d8ef31d54ba20.png)
(1)若方程组的一个解为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25f114df5ceabdb7e5fd3fdad4eaf056.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632244ea6931507f8656e1cc3437d392.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb0d7fbcc396c7b646c31f60e32d9e76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc6abf3f9b0ebcdc47a028c781b7edb9.png)
(3)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a7bb2271f0c1ae6f267beff842fcc44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88edfcabd49166a6dae74eecbdafd35f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
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名校
4 . 请同学们补全下面两个关于x的不等式的解答过程.
(1)
;
解:令
,
令
,计算
,
当
时,即
时,方程
不存在实根;
画
草图,
不等式的解集为______.
当
时,即______时,方程
的两根为______.
画
草图,
不等式的解集为______.
当
时,即______时,方程
的两根为______.
画
草图,
不等式的解集为______.
(2)
.
解:令
(*),
则方程(*)的三个根从小到大排列分别为
______;
______;
______.
把三个根分别标在x轴上,并完成表格,
请根据表格写出不等式
的解集.
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/458cbcd84273373e0a0bdab32ad42bad.png)
解:令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a4317c59a6012372bc027d7badec24f.png)
令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06295591972865ce5a2fafb1427aa707.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5c70eef4e278303db019587ee2cc20f.png)
当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc39e3f9688bc77675ffdf0dd79da142.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6232dc74b15e4acb0ac3482a1cbe6a52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06295591972865ce5a2fafb1427aa707.png)
画
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/925d9d720033e5e20561eb5f0722ecef.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/6/b7500d30-d563-4620-8611-50152041ac5f.png?resizew=165)
不等式的解集为______.
当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c2b0eb6b8e515c616b5cdd4c37fefc3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06295591972865ce5a2fafb1427aa707.png)
画
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/925d9d720033e5e20561eb5f0722ecef.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/6/f7cb6ca2-bf56-448e-896a-91b0659d6ed3.png?resizew=164)
不等式的解集为______.
当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dda1e6337ff7355c2fe9c19f9d619f5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06295591972865ce5a2fafb1427aa707.png)
画
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/925d9d720033e5e20561eb5f0722ecef.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/6/3bdfb626-c867-473d-bcff-8423f5c61714.png?resizew=166)
不等式的解集为______.
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fef1d654789c54f96acda1437cffb865.png)
解:令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d8fa5322900d260782795939a4085c3.png)
则方程(*)的三个根从小到大排列分别为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e92f14fb20f920f88dcad2ccd1d53f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15dad5a12f34bed0da0de93beae0eaa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e7ad31dd3397f7d2830182a8d309289.png)
把三个根分别标在x轴上,并完成表格,
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/6/9af896b0-08b8-4ac2-980e-9da2035e8cbd.png?resizew=271)
x的取值范围 | ||||
|
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fef1d654789c54f96acda1437cffb865.png)
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名校
5 . 成书于约两千多年前的我国古代数学典籍《九章算术》中记载了通过加减消元求解
元一次方程组的算法,直到拥有超强算力计算机的今天,这仍然是一种效率极高的算法.按照这种算法,求解
元一次方程组大约需要对实系数进行
(
为给定常数)次计算.1949年,经济学家莱昂提夫为研究“投入产出模型”(该工作后来获得1973年诺贝尔经济学奖),利用当时的计算机求解一个42元一次方程组,花了约56机时.事实上,他的原始模型包含500个未知数,受限于机器算力而不得不进行化简以减少未知数.如果不进行化简,根据未知数个数估计所需机时,结果最接近于( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31ea24c4c625df0f9c8a348cbe9edb6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2022-12-05更新
|
304次组卷
|
3卷引用:北京市海淀区北大附中2023届高三预科部上学期12月阶段练习数学试题
解题方法
6 . 一学生解方程
,经过
换元变形后得到
,为求解方程,他判断出方程无有理根.利用二分法,发现两个零点
满足
,他决定追踪之并分解因式,得到下表.
则下列实数中,关于x的方程的解为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95e35b4867331007ef3a99c8f70dd253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7d742e1206acd2584184528a21e99b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7f4bed01737f952037308d17a4243ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ae8e9f49a0c2862c0672ff6e12454be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cea65015d5c56a26b0fdd77f6359fd1.png)
t | 0 | 1 | 0.5 | 0.75 | 0.625 | 0.562 | 0.593 | 0.609 | 0.617 | 0.621 | 0.619 | 0.618 |
9 | 1.613 | 0.060 | 0.025 | 0.008 |
A.![]() | B.![]() | C.![]() | D.![]() |
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名校
7 . (1)解关于x,y的方程组![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee94cad924f3bde7a583545b6ac84012.png)
(2)已知
和
是关于x,y的方程组
(k为参数)的两组不同实数解.
求证:①
,
;
②
;
③
(其中
).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee94cad924f3bde7a583545b6ac84012.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3396ead2a01ebd1d6134732541008a7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/734a03b0e1c4de970668548ebb944fc0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/494c830fbe4b161a0d1506c1aaf15cfb.png)
求证:①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fda10b954abfc6bcd2fa0fe54536bcfe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fa675d90df61bdb59aa45a3654c6a71.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d28790c9a69068d3ce4caafae10a967.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/681683ea78209722151377053b34d082.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2851fd014aec602364532b264691c271.png)
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8 . 设
是方程
的一组解,计算:
(1)
;
(2)求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cad0086651e05c716cec1ba31cf09f1c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c82e7d9f4f7ace849e09e9adcb786b7f.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/821dc5767ac7967687426e4b9c46c918.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b859b72b8127df011d0b3032d2c3ff3e.png)
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9 . 某同学解答一道解析几何题:“已知圆
:
与直线
和
分别相切,点
的坐标为
.
两点分别在直线
和
上,且
,
,试推断线段
的中点是否在圆
上.”
该同学解答过程如下:
请指出上述解答过程中的错误之处,并写出正确的解答过程.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4896f254406ddfe0744b63f10724e76a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e52f174a2372c95fc2a5a1f4bea0ee5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4187fed72b21e7e74f1eb195633ed62d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc6554ac3dff4a59833e407db887f6e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1578b2282112e75c9e09fa24c62103df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
该同学解答过程如下:
解答:因为 圆![]() ![]() ![]() ![]() 所以 ![]() 所以 ![]() 由题意可设 ![]() 因为 ![]() ![]() ![]() 所以 ![]() ![]() 因为 ![]() 所以 ![]() 化简得 ![]() 由①②可得 ![]() ![]() 所以 ![]() 因式分解得 ![]() 所以 ![]() ![]() 解得 ![]() ![]() 所以 线段 ![]() ![]() ![]() 所以 线段 ![]() ![]() |
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解题方法
10 . 已知函数
.
(1)若
,写出不等式
的解集;
(2)从下列条件中只选出一个条件作答,使得函数
在
上有最小值,把选出的条件填在横线上,并写出
的单调区间及最小值;__________.(若选择的条件没有最小值,则本小题不得分)
①
;②
;③![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65397f11ea8af736f38debadf420c4a.png)
(3)解关于
的不等式
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0377ee50123c2b689ae92f391ab5f387.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c73a98c1b3504e09bfbe0db849b0d24.png)
(2)从下列条件中只选出一个条件作答,使得函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b69abe959988e4c8c0739f5857ccfb0f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b4d795709b0abcf47bceec2250f2f9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e258ab9e600435b37465092243d99f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65397f11ea8af736f38debadf420c4a.png)
(3)解关于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a71baf6217604517fd98fa97d0f55b43.png)
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