Limit thought is an important thought in modern mathematics, and mathematical analysis is a subject that studies functions with the concept of limit and limit theory (including series) as the main tools. The thought of limit refers to "a mathematical thought to analyze and solve problems with the concept of limit".
The general steps to solve problems with extreme ideas can be summarized as follows:
For the unknown quantity to be investigated, first try to correctly conceive another variable related to its change, and confirm the influence trend of this variable through the infinite change process. The result is very accurate and approximately equal to the unknown quantity. The result of the unknown quantity under investigation can be calculated by the limit principle.