根轨迹上的点必须满足相角条件和幅值条件：
- 相角条件：\(\begin{gathered}\sum_{j=1}^m \angle\left(s-z_j\right)-\sum_{i=1}^n \angle\left(s-p_i\right)=(2 k+1) \pi \\k=0, \pm 1, \pm 2, \cdots\end{gathered}\)
- 幅值条件：\(K^*=\frac{\prod_{i=1}^n\left|s-p_i\right|}{\prod_{j=1}^m\left|s-z_j\right|}\)
| status | not read | reprioritisations | ||
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| last reprioritisation on | suggested re-reading day | |||
| started reading on | finished reading on |