X stands for unknown and any number. Unknown is a value to be determined when solving an equation, and it is also used as a metaphor for things that are not known yet. In mathematics, symbols X or Y are often used to mark unknowns. They can be used in equations or inequality relations to help us solve problems.
In ancient China, unknowns were not represented by symbols, but equations were solved by calculation. In the Song and Yuan Dynasties, Li Zhi used "Li Tianyuan" to express the unknown, and wrote a yuan word as a symbol beside the corresponding coefficient. In the Yuan Dynasty, Zhu Shijie (about13rd century) expressed four unknowns in terms of heaven, earth, people and things, and established the theory of four-dimensional higher-order equations. The name of the element in the problem of elimination in mathematics also comes from this.
meaning
The 24th letter X of the English alphabet is equivalent to the 22nd letter χ (chi) of the Greek alphabet. In fact, the former is borrowed from the latter, while the latter comes from a Phoenician hieroglyphic letter representing "fish", which sounds like samekh.
X stands for10 in Roman numerals; In algebra and mathematics, x is usually used to represent the unknown. When algebra was introduced into Europe from Arabia, the word shei, which means "unknown" in Arabic, was translated into xei, so the initials X became the common code name of unknown. There is another saying about the origin of the letter X: X was originally a pictographic symbol for kissing, written as χ, which looks a bit like two mouths kissing. And this explanation may be a folk etymology.
translate freely
1, a mathematical term. Refers to the number that needs to be calculated in an algebraic expression or equation to determine or get the relationship with other unknowns. It also refers to things that have not yet been understood.
Wei Wei's "Oriental" Chapter 17: "When this distant goal is unknown, our own ship has crashed into the rocks."
2, refers to uncertain or uncertain things, such as "what will happen in the future is unknown, no one will know."