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Root-Locus Method

Complex Numbers as Vectors in Polar Form

Description

Complex numbers can be shown as vectors, not just as points in Cartesian coordinates. In polar form, a vector is described by its magnitude, or length, and its angle. This makes complex numbers easier to compare by size and direction.

The same idea also helps describe complex functions. When a co...

Transcript

用笛卡尔坐标描述的复数可以表示为矢量。这些复数可以用极坐标形式表达,展示其模长和角度。

当复数作为输入传递给一个函数时,其结果是另一个复数。这突显了一个关键特征:函数的零点,即向量表示的起始点。

考虑一个函数,其定义为复因子分子的乘积除以分母的乘积。

由于每个复数因子本质上是一个矢量,因此函数在任意点的幅值等于零点长度的乘积除以极点长度的乘积。

该函数的角度计算为极点角度之和减去零点角度之和。这些角度是从实轴正方向开始测量的,即从函数的零点或极点向给定点所作向量与实轴正方向之间的夹角。

为了求解特定点上的复变函数,需计算从函数的零点和极点出发并终止于所选点的向量。代入向量方程可得到其模长和相位角。