2024高三·全国·专题练习
1 . 下面是应用公式
,求最值的三种解法,答案却各不同,哪个解答错?错在哪里?已知复数
为纯虚数,求
的最大值.
解法一:∵
,
又∵
是纯虚数,令
(
且
),
∴
.
故当
时,即当
时,所求式有最大值为
.
解法二:∵
,∴
.
故所求式有最大值为
.
解法三:∵
,
又∵
为纯虚数,∴
,
∴
.
故所求式有最大值为
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b24b1f5fe3cf65914e79532f4d2b23d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e81e59019989b7dc2fb59b037ef6e010.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e3958fbc45ee3e72d9a6dc37a8f9474.png)
解法一:∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8201b70b4e9a66d8843dff2e728199c.png)
又∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e81e59019989b7dc2fb59b037ef6e010.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cdecf72a044cbeb148db4e743c52514.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dd0914dc4d4c7f75710ff460a286fcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b03b011f69dfc5262a3d82f64676739b.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7794d59445d4545e6fd58d484fef86d3.png)
故当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a3c442579603164f3fc19458677d307.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/128730d6a25a11ed9b6b0f0e7f4f0433.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b7e9bd225e22d3c95a681720114056f.png)
解法二:∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a61f82d3db0076d8d07b901691021f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c186e2d43b0f52ff872a3613d56f8b1.png)
故所求式有最大值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/934c6d8e32b31bdcfa263c705b95182b.png)
解法三:∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62981b55a133db7d326bef9d3e73b4c2.png)
又∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e81e59019989b7dc2fb59b037ef6e010.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed98359cf005d2b49ec68f55d1f87c6e.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c56d0e6036bae5d5a30c2a1f9fff19a0.png)
故所求式有最大值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c296c04fc52c07364a234c0ac6233022.png)
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2 . 类比复数加法的几何意义,请写出复数减法的几何意义.
您最近一年使用:0次
2023-10-09更新
|
30次组卷
|
3卷引用:2.1 复数的加法与减法
3 . 已知复数
,
,
,分别记作
,
,
,即
,
,
,求证:
(1)
;
(2)
;
(3)
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e840ea0100bed41c779ba4d30fee7670.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4160c2acea59936bd06a7d7a7aa4514.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/491ff1d34a2e0b5c35ec5b482f9e6dc1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af68f652b4c13657ffddf3c9e7eb262b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa224ed9be8766a4d0b5138bd57de0f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a67a742d2a43e907fb1c3a1bdf1d6a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7769a9ed79bc3d423437e1ed98b033af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/935a9ada9a7372c5d296243c435a3c73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf111e7aa8784c1c67b30e1a2ad3671c.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f06ca9d2cc05ecc6fbe8022f12002632.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e866b8803b38e56c63e811cde5885cf.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dc05d7f017b7a96b162888d4162254c.png)
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2023-01-06更新
|
149次组卷
|
4卷引用:沪教版(2020) 必修第二册 新课改一课一练 第9章 9.1 复数及其四则运算
沪教版(2020) 必修第二册 新课改一课一练 第9章 9.1 复数及其四则运算(已下线)专题7.4 复数的四则运算(重难点题型检测)-2022-2023学年高一数学举一反三系列(人教A版2019必修第二册)(已下线)12.2 复数的四则运算(2)-2022-2023学年高一数学《考点·题型·技巧》精讲与精练高分突破系列(苏教版2019必修第二册)(已下线)专题7.4 复数运算的综合应用大题专项训练-举一反三系列-
4 . 如图所示,已知复数
,
所对应的向量
,
,它们的和为向量
.请根据两个向量相加的运算写出对应的复数运算过程.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7769a9ed79bc3d423437e1ed98b033af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc358e9ddfe2e61a2f3ebd4273de848c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/612af62da1c0563e32852f2e8122ee1b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43c6f2f26d1cd1232a8902de0177e395.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4407c0b2e5febf70f610bd00067f105.png)
![](https://img.xkw.com/dksih/QBM/2021/12/1/2863252955602944/2863403750727680/STEM/59180b8be78041e4af71565ea581733d.png?resizew=261)
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