For the unknown quantity under investigation, first try to correctly conceive another variable related to its change, and confirm that the trend result of the' influence' of this variable through the infinite change process is very accurate and approximately equal to the unknown quantity sought; The result of the unknown quantity under investigation can be calculated by the limit principle.
The thinking function of extreme thinking
Extreme thoughts are widely used in modern mathematics and even physics, which is determined by its inherent thinking function. The thought of limit reveals the unity of opposites between variables and constants, infinity and finiteness, which is the application of the law of unity of opposites of materialist dialectics in the field of mathematics.
With the help of limit thought, people can know infinity from finiteness, change from invariability, curve from linear formation, qualitative change from quantitative change and accuracy from approximation.
The two concepts of "infinity" and "finiteness" are different in essence, but they are related. Infinity is the concept of abstract thinking in the brain, which exists in the brain. "finiteness" is the mapping of ever-changing things that exist objectively, and "infinity" that conforms to the laws of objective reality belongs to the whole. According to axioms, the whole is greater than the local thinking.