题目
Find the complex numbers which satisfy the equation and are such that . Give your answers in the form , where and are real.
题目中文翻译
求满足方程 且满足 的复数 。答案以 的形式表示,其中 和 为实数。
原卷通用作答要求
Answer all questions. You should use a calculator where appropriate.
You must show all necessary working clearly; no marks will be given for unsupported answers from a calculator.
Give non-exact numerical answers correct to 3 significant figures, or 1 decimal place for angles in degrees, unless a different level of accuracy is specified in the question.
请回答所有题目。适当时应使用计算器。必须清楚展示所有必要的计算过程;仅给出计算器答案而没有过程,不予评分。除非题目另有精度要求,非精确数值答案保留 3 位有效数字,以度为单位的角度保留 1 位小数。
解答
解法一
思路
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设 ,代入时共轭为 。比较实部、虚部后,虚部可分解成两个分支,最后用实部限制筛选。
答题过程
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Let , with real. Then , so
Equating parts gives
If , the real equation gives
so and .
If , the real equation gives , so . The requirement selects .
Therefore