1, if you get a specific number after substitution, it is the limit.

2. If you get infinity after substitution, the answer is that the limit does not exist.

3. If it is uncertain whether it is a specific number or infinity after substitution, it is an infinitive type.

4. Calculating the limit means calculating the tendency of the trend.

Existence conditions:

Monotone bounded theorem In real number system, monotone bounded sequence must have a limit.

Compactness theorem, any bounded sequence must have a convergent subsequence.

Calculation method, refer to the figure below:

The limit problem of sequence is an important part of our study, and the limit theory is also one of the foundations of higher mathematics. As a basic concept of calculus, the limit problem of sequence is of great significance to calculus theory.

Restrictions:

Think about solving problems:

References:

Baidu encyclopedia-sequence restriction