名校
解题方法
1 . 已知函数
.
(1)证明:
;
(2)设函数
,若
恒成立,求
的最小值;
(3)若方程
有两个不相等的实根
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc36a3c21811a9754a537062a73f43e6.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e799e937076aa5a7dcd51cdc0f40f6b0.png)
(2)设函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5706e65074de43ba1d3b0f5861646e1e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daa18838a13fda4e45612c32cdf98b71.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
(3)若方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9c0d827ef8598ba6b70b34b2bdcd1e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ce7ae90d808f05e86ea063238e4b2f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f98def21c9ea5780553a3dfb46d455f.png)
您最近一年使用:0次
名校
解题方法
2 . 设实系数一元二次方程
①,有两根
,
则方程可变形为
,展开得
②,
比较①②可以得到![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71e360b7ba27dfc3e5d401027d5bd8a5.png)
这表明,任何一个一元二次方程的根与系数的关系为:两个根的和等于一次项系数与二次项系数的比的相反数,两个根的积等于常数项与二次项系数的比.这就是我们熟知的一元二次方程的韦达定理.
事实上,与二次方程类似,一元三次方程也有韦达定理.
设方程
有三个根
,则有
③
(1)证明公式③,即一元三次方程的韦达定理;
(2)已知函数
恰有两个零点.
(i)求证:
的其中一个零点大于0,另一个零点大于
且小于0;
(ii)求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c3f3db6b7c682450309a6ccba5ac5a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ce7ae90d808f05e86ea063238e4b2f9.png)
则方程可变形为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/455d33fcfd9a59d6b374e9d25888cd2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e42b42152492cbdfec62c7a02be4055.png)
比较①②可以得到
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71e360b7ba27dfc3e5d401027d5bd8a5.png)
这表明,任何一个一元二次方程的根与系数的关系为:两个根的和等于一次项系数与二次项系数的比的相反数,两个根的积等于常数项与二次项系数的比.这就是我们熟知的一元二次方程的韦达定理.
事实上,与二次方程类似,一元三次方程也有韦达定理.
设方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ddc5e3c2c7c6f4d2d0ab396b65679a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05b8ec9d4206ea66a02de5c4a1e1e911.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb8d75a2417827b2c5b09ba9385fe252.png)
(1)证明公式③,即一元三次方程的韦达定理;
(2)已知函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2b5e4746c2bd0afb279630698afd3a0.png)
(i)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d275fbb3ee5cd1177ca5a2ceecbbef0f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274a9dc37509f01c2606fb3086a46f4f.png)
(ii)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20d6fc9b90f370fbb27552876b650f8f.png)
您最近一年使用:0次
解题方法
3 . 已知函数
.
(1)当
时,证明:
;
(2)已知
,
,求证:函数
存在极小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2d44d5e638a975bc93491659a141d8c.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd876a2ed79c64bacc3e64b8ee92735e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29cee707aaa2ee5798e38b9624dc396e.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c80cd7a435009b8713641e5ff655179a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cb319ba3ed05f5ad4c9f56b40e43e1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/028517e8bebe634441e0a5c79828e88a.png)
您最近一年使用:0次
4 . 已知函数
.
(1)求
在
处的切线方程
,并证明
的图象在直线
的上方;
(2)若
有两个不相等的实数根
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d4b35e41dfa9391bf5004948d4ed574.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b384412acba251d87902ab928902f16.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b331497342e72895c306815d1cca62b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b222b256b37f83fa24a3a4b6527f58d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f5dc5d64a9a86dd15c47e7d129fc622.png)
您最近一年使用:0次
名校
5 . 已知函数
,其中
.
(1)求曲线
在
处的切线方程
,并证明当
时,
;
(2)若
有三个零点
,且
.
(i)求实数
的取值范围;
(ii)求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38f7bac7520fa44f299a861781626472.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10bbdef421c976962a270a2beabbad91.png)
(1)求曲线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51c530f4b7491b95acb8ce3eef9aa09d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bea9227dd0104da58e0c40952cc87ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a1cfb60420ff7e72c1b9d64f69ae063.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fde64f4d3c38e43fbdee24eadc4b0dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8821abd8dda8b7cbfec152700ef79f4.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05b8ec9d4206ea66a02de5c4a1e1e911.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1310a7a80d1f8751a3f8cafe7f8c8b4.png)
(i)求实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(ii)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6eb8404a0443abc179871b8ebefbf9fb.png)
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6 . 已知函数
,
.
(1)证明:
.
(2)设方程
有两个实根
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1c0dc2a7d473b322fed4e2a48770394.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3667e0dff78601b93c935881ba85542b.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44e312eca38032174f9739126b81d012.png)
(2)设方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ff6838d84b68c6f0d3b93b196d9b08d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2aabc96b7433bba077ceac76d8f0d75.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93e6c90e91a4e6316e1a111719c16e8e.png)
您最近一年使用:0次
名校
解题方法
7 . 已知函数
,
.
(1)当
时,求证:
;
(2)当
时,
恒成立,求实数
的取值范围;
(3)已知
,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6b1868d9850b7103e1326eb001dfbce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9100abe06c208f6742dc75861a33989.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daa18838a13fda4e45612c32cdf98b71.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adc3e5be1796493161a4df7e28a6f6b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daa18838a13fda4e45612c32cdf98b71.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(3)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2aa78c96db411c9e1e939ae16de78d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d062874efc06af87693c548b09fbc91.png)
您最近一年使用:0次
2023-11-30更新
|
427次组卷
|
3卷引用:江苏省镇江市扬中高级中学2024届高三上学期十月学情检测数学试题
名校
解题方法
8 . 已知函数
(
,其中
为自然对数的底数).
(1)求曲线
在点
处的切线方程;
(2)若
,证明:
有且只有一个零点,且
;
(3)当
时,若
且
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a44a0ebcb7013657595435b9128a4cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4799629218b4b62ffa4082b96888e3c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/041a7c8fc017f596542c5e6ec7d1c40b.png)
(1)求曲线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51c530f4b7491b95acb8ce3eef9aa09d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea338c001863343dc97e426b2f6b5251.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a4b04824a308519a61318a82aa97a05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adb1dc30d4b297c6d5d0d6d91eab1e3b.png)
(3)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e436ea3ddcd13e69171135f0ff8e934a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1650819534a0ae5d0be19a26cb7e7cbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33bd24e647a626899a243a3f3984f90a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a482f0d2bde5f7df317acc4a86c50f5.png)
您最近一年使用:0次
名校
9 . 已知函数
.
(1)求曲线
在点
处的切线方程;
(2)设
,求证:当
时,
;
(3)对任意的
,判断
与
的大小关系,并证明结论.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c38e2cfb9e16f2f5d7a1e9a7590dd073.png)
(1)求曲线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51c530f4b7491b95acb8ce3eef9aa09d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68c6b6a11760d0724b0b60e55970e229.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/585de67a3fc494297d375d339af6d153.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b79ae1ceee652b06fc889607ff3f1df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fa38ca27c6c0c40d5e36b2ae4fb7ba7.png)
(3)对任意的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c975a637794e6be6dd95e1e1ba12620.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/baa9fca7538f46d9d2b4429dd085ac78.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d4fc8faefb26b233d4aa9dbef043aae.png)
您最近一年使用:0次
2023-06-18更新
|
427次组卷
|
2卷引用:北京市大兴区2022-2023学年高二下学期期中考试数学试题
解题方法
10 . 已知函数
.
(1)证明不等式:
,
;
(2)若
,
,使得
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02e41217f3039effba4b352e7ae68deb.png)
(1)证明不等式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a623d70dccf0773e19310b4cc863fbd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac4cbc7b067862a3d9c6789b392fc068.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9be23b1d40d59f429f2f90c814815491.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33bd24e647a626899a243a3f3984f90a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cd6f48770212bd0382da5dbab6d95c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d136fd3c66c833cc3cf80cbf0b2870b1.png)
您最近一年使用:0次
2022-12-09更新
|
331次组卷
|
2卷引用:广西贵港市2023届高三毕业班上学期12月模拟考试数学(理)试题