1 . (1)对实系数的一元二次方程可以用求根公式求复数范围内的解,在复数范围解方程
;
(2)对一般的实系数一元三次方程
(
),由于总可以通过代换
消去其二次项,就可以变为方程
.在一些数学工具书中,我们可以找到方程
的求根公式,这一公式被称为卡尔丹公式,它是以16世纪意大利数学家卡尔丹(J. Cardan)的名字命名的.卡尔丹公式的获得过程如下:三次方程
可以变形为
,把未知数
写成两数之和
,再把等式
的右边展开,就得到
,即
.将上式与
相对照,得到
,把此方程组中的第一个方程两边同时作三次方,
,并把
与
看成未知数,解得
于是,方程
一个根可以写成
.
阅读以上材料,求解方程
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed344791b8b035ca04d4b5af7364cae5.png)
(2)对一般的实系数一元三次方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48ad9d68d15b5d5121fcf99ebddaa986.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20849c00c47cbdc43f18d53341b6c4e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae0f3c81f415857813838d4b9b714d56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ea05ab19c339e26f8268fbc7b6e918d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5dd275a6062b21f9c3e9155c7e0ba62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5dd275a6062b21f9c3e9155c7e0ba62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ead1b77b69e6b51d6d483331fd01d41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0bed1a02239821a616bc173181e7ed2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c26aacdd3362aa65b2966045cbfcddf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f02c3aa1326c9b1e069b6997cd29bfa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11792ad247341c0dbc80663dd0fa6f77.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ead1b77b69e6b51d6d483331fd01d41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1e8aa11c220ffef18a553784e1ecc16.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/491db400b0e81be11e3fd8729fe61a41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36accab23dbd172687769aea43e5781c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411a315870ed3e6d0e8ea885f1a04bcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a9930c09269f4f03794e38c17f6da67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5dd275a6062b21f9c3e9155c7e0ba62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49d63387694fd1caafce80adfb43c86b.png)
阅读以上材料,求解方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93c3d494147195cf4f5e1fa3f6f5a0b9.png)
您最近一年使用:0次
2 . 对一般的实系数一元三次方程
,由于总可以通过代换
消去其二次项,就可以变为方程
.在一些数学工具书中,我们可以找到方程
的求根公式,这一公式被称为卡尔丹公式,它是以16世纪意大利数学家卡尔丹(J.Cardan)的名字命名的.
卡尔丹公式的获得过程如下:三次方程
可以变形为
,把未知数x写成两数之和
,再把等式
的右边展开,就得到
,即
.将上式与
相对照,得到
,把此方程组中的第一个方程两边同时作三次方,
,并把
与
看成未知数,解得
,于是,方程
一个根可以写成
.
阅读以上材料,求解方程
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eccb3856fa5aa8dc822a593ec88ca2bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae0f3c81f415857813838d4b9b714d56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5dd275a6062b21f9c3e9155c7e0ba62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5dd275a6062b21f9c3e9155c7e0ba62.png)
卡尔丹公式的获得过程如下:三次方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5dd275a6062b21f9c3e9155c7e0ba62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ead1b77b69e6b51d6d483331fd01d41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0bed1a02239821a616bc173181e7ed2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c26aacdd3362aa65b2966045cbfcddf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f02c3aa1326c9b1e069b6997cd29bfa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11792ad247341c0dbc80663dd0fa6f77.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ead1b77b69e6b51d6d483331fd01d41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7a28d84fa30daeb6cfcb0347d1d40a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/718a7346b05d9a0c4f31a60d8786404b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36accab23dbd172687769aea43e5781c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411a315870ed3e6d0e8ea885f1a04bcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b79aba80a3fc337b27ed567abf1e5c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5dd275a6062b21f9c3e9155c7e0ba62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49d63387694fd1caafce80adfb43c86b.png)
阅读以上材料,求解方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93c3d494147195cf4f5e1fa3f6f5a0b9.png)
您最近一年使用:0次
名校
解题方法
3 . (1)计算
;
(2)已知关于
的方程
有实数解,求纯虚数
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ae6e91f961e6c375860251f88519329.png)
(2)已知关于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/752a8ba32cdcfb5d8e77f2f84d5acdb6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
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4 . (1)计算:的值;
(2)在复数范围内解关于的方程:
;
(3)设复数,
满足
,
,求
的值.
您最近一年使用:0次
解题方法
5 . 1799年,哥廷根大学的高斯在其博士论文中证明了如下定理:任何复系数一元
次多项式方程在复数域上至少有一根(
).此定理被称为代数基本定理,在代数乃至整个数学中起着基础作用.由此定理还可以推出以下重要结论:
次复系数多项式方程在复数域内有且只有
个根(重根按重数计算).对于
次复系数多项式
,其中
,
,
,若方程
有
个复根
,则有如下的高阶韦达定理:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68be203b2490ecce4c0e2eadeb5d911b.png)
(1)在复数域内解方程
;
(2)若三次方程
的三个根分别是
,
,
(
为虚数单位),求
,
,
的值;
(3)在
的多项式
中,已知
,
,
,
为非零实数,且方程
的根恰好全是正实数,求出该方程的所有根(用含
的式子表示).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e167b43045b3297248e334c41c621b8f.png)
![](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/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b024d78f428194127b5534f948810def.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7230de53663c75658c58bbf206a0085.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bed25da42194b5a81d123933d5704f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd3759b3561834cdc5b499b91f3850d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86b92b70365c63607daecdc8deb73ecf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c83590c4a7ea5636843dd4b60c67cb40.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68be203b2490ecce4c0e2eadeb5d911b.png)
(1)在复数域内解方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4800c5aa0e5b70b2141541cbd3853e34.png)
(2)若三次方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac603c0b3d1d7fd42bd50222b6ab94d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6755cd39b121a0dd2a14da8d43c1fff4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ddb97874a62bb5530514a467d64af13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8079c5a2d8674d322f7abe6d4ef4a3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a7035cd4adda5d72a9fc9f9fda75995.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
(3)在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5818ede14d21f6df9ef9c2bfe09286c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b024d78f428194127b5534f948810def.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cb3db0a99f86232e0cf3e55c789ea99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e2e2674707c28eddd3f3ab60f73f54f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c37d6353f394a5704a92113908a5c3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86b92b70365c63607daecdc8deb73ecf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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解题方法
6 . 已知
是复数,
与
均为实数.
(1)求
;
(2)若复数
是方程
的一个解,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e81e59019989b7dc2fb59b037ef6e010.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/005f6a19fe7b2709a8447830ea0a024a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c32849bfd957f6f3bba6f29dfefc388.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01ea3cc01ce7266cdf0fd73fd50d23c8.png)
(2)若复数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e81e59019989b7dc2fb59b037ef6e010.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ae9ab71d1179a20680652f8c68e77c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72850427e83ff19a24305783e080b280.png)
您最近一年使用:0次
2024-05-09更新
|
368次组卷
|
3卷引用:福建省泉州第五中学2023-2024学年高一下学期期中考试数学试题
福建省泉州第五中学2023-2024学年高一下学期期中考试数学试题(已下线)专题06 复数-期末考点大串讲(人教B版2019必修第四册)江苏省宿迁市泗阳县两校联考2023-2024学年高一下学期第二次学情调研(5月月考)数学试题
2024高三·全国·专题练习
7 . 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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名校
解题方法
8 . 已知复数
、
是方程
的解.
(1)
的值;
(2)若复平面内表示
的点在第三象限,
为纯虚数,其中
,求
的值.
![](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/f2d7dc3fa43ef2ed97945ce21a208d42.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60e487d5357e01ee9df8526cd0f37a8b.png)
(2)若复平面内表示
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af68f652b4c13657ffddf3c9e7eb262b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3893f025b225f22f5fb6f8ea71aa9c3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22dd8b3dc4c609bab82d356a5cc2208d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
您最近一年使用:0次
2023-07-28更新
|
349次组卷
|
4卷引用:FHsx1225yl191
(已下线)FHsx1225yl191(已下线)【高一模块二】类型3 以复数为背景的解答题(B卷提升卷)山东省临沂市罗庄区2022-2023学年高一下学期期中数学试题江西省萍乡市安源中学2022-2023学年高一下学期期末质量检测数学试题
解题方法
9 . 已知复数是方程
的解,
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e81e59019989b7dc2fb59b037ef6e010.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13997a98685e66487800de874015cbb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebd1cf228141f1668f0f2015e534178a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73254f32b6da29ecc32df2e9f87a4c97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a7035cd4adda5d72a9fc9f9fda75995.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fff0f1b6dd0be54207299f6c22eec25f.png)
您最近一年使用:0次
2023-03-02更新
|
561次组卷
|
5卷引用:7.2.2复数的乘、除运算(第2课时)
(已下线)7.2.2复数的乘、除运算(第2课时)上海市民办丰华高级中学2021-2022学年高一下学期期末数学试题(已下线)专题强化 复数高频考点一遍过精练必刷题-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)浙江省温州新力量联盟2022-2023学年高一下学期期中联考数学试题(已下线)核心考点02复数(2)
名校
解题方法
10 . 在英语中,实数是Real Quantity,一般取Real的前两个字母“Re”表示一个复数的实部;虚数是Imaginary Quantity,一般取Imaginary的前两个字母“Im”表示一个复数的虚部.如:
.已知复数
是方程
的解.
(1)若
,求证
;
(2)若
,复数
且满足
,在复平面内
对应的点为
,当
取得最大值时,求点
的坐标.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/485391d2213215f1b645d77cb12e1651.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/074c228ffc7b1e306f8410afe7bc4b5c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8646eaa05bfde39d27813c301a076420.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07b0e1c4446de1a064b9c11e96b288d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5be05f2449cfe1fb871512e40199b151.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36b34d58c444d285fe7ac7f6ca8d8bd8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db95214c54cc0785b910bcf465159555.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39e23f7a3a11395e3b7fc4c41f9d71e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e81e59019989b7dc2fb59b037ef6e010.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8b9ad2fcfff3dd546c5fdbedfe6238.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6447fb3ff7619b7c9e77e728bb14d18.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8b9ad2fcfff3dd546c5fdbedfe6238.png)
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