Limit "limit" is the basic concept of calculus, a branch of mathematics. The "limit" in a broad sense is "infinitely close and never reached". In mathematics, "limit" means that a variable in a function gradually approaches a certain value A in the process of getting bigger (or smaller), and "it can never coincide with A" ("it can never be equal to A, but taking a value equal to A' is enough to obtain a high-precision calculation result), and the change of this variable is artificially defined as" forever approaching ". Limit is a description of "changing state". The value a that this variable always approaches is called the "limit value" (of course, it can also be expressed by other symbols).
The origin of limit, like all scientific thinking methods, is also the product of abstract thinking in social practice. The idea of limit can be traced back to ancient times. For example, the secant technology in Liu Hui, the motherland, is an original and reliable application of the limit idea of "approaching constantly" based on the research of intuitive graphics; The ancient Greeks' exhaustive method also contained the idea of limit, but because of their "fear of infinity", they obviously avoided artificially "taking the limit" and completed the relevant proof by indirect proof-reduction to absurdity.
/kloc-in the 6th century, Steven, a Dutch mathematician, improved the ancient Greek exhaustive method in the process of investigating the center of gravity of a triangle. With the help of geometric intuition, he boldly used limit thought to think about problems and gave up the proof of reduction law. In this way, he inadvertently "pointed out the direction of the development of the limit method into a practical concept."