1 . 一般地,抛物线的三条切线围成的三角形称为抛物线的切线三角形,对应的三个切点形成的三角形称为抛物线的切点三角形.如图,
,
分别为抛物线
的切线三角形和切点三角形,
为该抛物线的焦点.当直线
的斜率为
时,
中点的纵坐标为
.
.
(2)若直线
过点
,直线
分别与该抛物线的准线交于点
,记点
的纵坐标分别为
,证明:
为定值.
(3)若
均不与坐标原点重合,证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ed4022e6522665dab4ce898a539e5c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b6d8eaacc2d999b37209feba103f9ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acbc6a613224461ade69362d46550474.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274a9dc37509f01c2606fb3086a46f4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/374fe9986ebbc986fc422e514ab93a51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91e1e4115d78e625e9e0f47cdade3286.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91e1e4115d78e625e9e0f47cdade3286.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5c0ba21d81e9f78014ea501cd494af5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26690f078768c54d833988769b8bc425.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/120c51a5eda9524a1e187420c0c8bac6.png)
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名校
2 . 由若干个平面多边形围成的几何体叫做多面体,围成多面体的各个多边形叫做多面体的面,两个面的公共边叫做多面体的棱,棱与棱的公共点叫做多面体的顶点.对于凸多面体,有著名的欧拉公式:
,其中
为顶点数,
为棱数,
为面数.我们可以通过欧拉公式计算立体图形的顶点、棱、面之间的一些数量关系.例如,每个面都是四边形的凸六面体,我们可以确定它的顶点数和棱数.一方面,每个面有4条边,六个面相加共24条边;另一方面,每条棱出现在两个相邻的面中,因此每条棱恰好被计算了两次,即共有12条棱;再根据欧拉公式,
,可以得到顶点数
.
(1)已知足球是凸三十二面体,每个面均为正五边形或者正六边形,每个顶点与三条棱相邻,试确定足球的棱数;
(2)证明:
个顶点的凸多面体,至多有
条棱;
(3)已知正多面体的各个表面均为全等的正多边形,且与每个顶点相邻的棱数均相同.试利用欧拉公式,讨论正多面体棱数的所有可能值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad4e1f7f53a3c6d988ce09f140255031.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/168b3e4b1d6f04226fa2687a72a268b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca4ff0af96ea467337cb30c4c765b5f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd3eb4e7cb0cbf60dcd981c7c088d7fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08ec5d76db9bd05547932966c9913dc2.png)
(1)已知足球是凸三十二面体,每个面均为正五边形或者正六边形,每个顶点与三条棱相邻,试确定足球的棱数;
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1135ff484a9f35e45865fd684b6a0e21.png)
(3)已知正多面体的各个表面均为全等的正多边形,且与每个顶点相邻的棱数均相同.试利用欧拉公式,讨论正多面体棱数的所有可能值.
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2024高三下·全国·专题练习
3 . 已知函数
(
).
(1)求
的单调区间;
(2)若函数
,
是函数
的两个零点,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6233ad1c7907e8cbbb86e3001f0535b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10bbdef421c976962a270a2beabbad91.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4669810732b633b60dbeaf0bf57204f6.png)
(2)若函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0782afef8772acb852c36a0befa92f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2aabc96b7433bba077ceac76d8f0d75.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3951a7bf1d9ca025aeef96c5c60411bd.png)
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4 . 已知函数
.
(1)当
时,求证:
存在唯一的极大值点
,且
;
(2)若
存在两个零点,记较小的零点为
,t是关于x的方程
的根,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9250ac88895db27b0ccb5869b0e8bf19.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79b752f0f189e5d8666daea73e145dff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84ffe0afc6fa9e62ff75d13f656e7cc4.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17f7f01bcb51cd8fd65827c26b065a99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7867f9fdfa7811958bf68b7ef10dd792.png)
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5 . 已知函数
,其中
.
(1)当
时,
,求
的取值范围.
(2)若
,证明:
有三个零点
,
,
(
),且
,
,
成等比数列.
(3)证明:
(
).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67f1fbd89d2a6c03f0afb467ad2afce5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10bbdef421c976962a270a2beabbad91.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b8c164755dc2d7cff80fb4c9cffc9be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22e38c541dec8fce1d26886e5ef7d21f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/301605e86e5a5e61a65c91cd3dd8b77e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aec19b68e3add9d5bfcc6269a1855b87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/291c25fc6a69d6d0ccfb8d839b9b4462.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1310a7a80d1f8751a3f8cafe7f8c8b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aec19b68e3add9d5bfcc6269a1855b87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/291c25fc6a69d6d0ccfb8d839b9b4462.png)
(3)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c8a263f0dff43a4febb0b511b41c0db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15a70b95c53fb6655721e2a8c61f5c2c.png)
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解题方法
6 . 已知函数
.
(1)当
时,证明:
是增函数.
(2)若
恒成立,求
的取值范围.
(3)证明:
(
,
).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/202753277c13024f87225c5b36dc72fe.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29c7572463225bb3b65cb371f4496440.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(3)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fd1360e5adc18f9007824381d8bc4e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0704f453b2de48d36911f7db496bbf82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac69e6db1df13ed64756b4f391ae9fac.png)
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7 . 若函数
在
上有定义,且对于任意不同的
,都有
,则称
为
上的“k类函数”.已知函数
.
(1)求曲线
在点
处的切线方程;
(2)求
的单调区间;
(3)若
为
上的“3类函数”,求实数a的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4776c85b79df196f606d3ebf3697fbc3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9d6fe21d6ed78bfc1d2b9cc41a766c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aeaea651d833a0fd5a2a7f0cbaeb4ae0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4776c85b79df196f606d3ebf3697fbc3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/485825faa883e045117e914fc4094908.png)
(1)求曲线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51c530f4b7491b95acb8ce3eef9aa09d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bea9227dd0104da58e0c40952cc87ed.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be1ce3f01e2b6364f9a9fdaf197d5e29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da34ce730f711c09909d53806fe2330a.png)
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2024高三下·全国·专题练习
8 . 已知函数
,
时,
,则实数
的范围是__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be8ab89740fb4824f71585d2e6b89067.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08115d6d9f876dea921a4d32260ff1fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59e17a5a943abe5c2c204a0946a1ed7a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
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名校
9 . 已知函数
.
(1)当
时,证明:
;
(2)当
时,
,求
的最大值;
(3)若
在区间
存在零点,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3fb69579884d02df940d0ee1577b5e1a.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd876a2ed79c64bacc3e64b8ee92735e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf9e6bfd0a580544713a59ed282bfe4a.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e541ea2f855f981c96207070683d388.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/213f600bc788894ff91df0356abb84f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d562dc22dfb3b81d0c3f88b54d063c2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
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