It can be said that the limit theory is the foundation of advanced mathematics, without which there would be no advanced mathematics. Because the core content of higher mathematics is undifferentiated, integral formulas and theorems are all proved by limit theory.

The methods of finding the limit can be divided into three categories:

Four algorithms and basic properties of 1. limit II. Two important limitations. Use derivatives.

The first category includes: method of substitution, reciprocal method, zero factor elimination method, physical chemistry method, infinitesimal infinite property method, pinch method, equivalent infinitesimal method of substitution, etc.

The second category is very clear, not much to say, just be flexible, and anything that conforms to the characteristics, that is, similar, will do.

The third category refers to Robita's rule and Taylor's expansion, which mainly solve the limit problem and energy formation problem of "0/0" and "∞/∞".