来自《耶鲁大学开放课程：基础物理 第16集 第16集》

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  It would be 36, you get i/2.
  也除以 36 就是 i/2
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  So, this number could have been 1/4+i/2.
  最后的结果为 1/4+i/2
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  So, dividing by a complex number is not a problem.
  复数除法我们也解决了
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  Now, why did I do all that stuff today about e^(i·x)?
  我今天为什么要讲 e^(i·x)
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  You're going to see that now.
  我这就来告诉你们
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  The rationale for going through that math is the following.
  介绍这么多数学应用的理由如下
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  Let's take this complex number
  我们假设有这么个复数
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  that goes from here to here, that is x+i·y
  为 x+i·y 如图中所示
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  And let's introduce, just like we would for an ordinary vector,
  跟我们在向量中的做法一样
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  this angle θ and that length r.
  定义此角度为 θ 线段长为 r
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  Whenever you have a vector,
  对于任意一个向量
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  you can talk about the Cartesian components x and y,
  既可以用笛卡尔坐标 x 和 y 来定义