This article defines the sensitivity of dispersed variable. And we can use it to analyze the order of a infinite and judge the convergence of a constant term series.

给出离散变量的灵敏度之定义，且通过变量的灵敏度分析无穷大量的阶，从而判断常数项级数的敛散性。

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Fixed cost a cost that does not vary with the volume of activity in the short term. (Also called Non-variable cost or Constant cost.)

固定成本短期内不随作业量而变化的成本。(又称“不变成本”或“恒定成本”。)

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