2. the coefficient of b: y on a straight line.
3. C: conic curve, constant term in quadratic function expression.
4.d: indicates the distance between two points or between a point and a straight line, and the tolerance in arithmetic progression.
5.e: the base of natural logarithm.
6, f, g, h: generally represents a function.
7.I: complex number (imaginary number)
8.j: Not too much.
9, k: the slope of the straight line
10, l: indicates a straight line.
1 1, m: unknown constant set.
12, n: the number of items in the series.
13, o: origin in coordinate system.
14, p: probability
15, q: common proportion in geometric series.
16, r: radius of circle.
17, s: area, sum of a series.
18, t: (unclear)
19, u, v: indicates a function, and v can also indicate a volume.
20.w: used in the plural to indicate a special plural.
2 1, x, y, z: unknown
Extended data:
The origin of English letters
English letters originated from Latin letters, which originated from Greek letters, which evolved from Phoenician letters and were deeply influenced by ancient Egyptian holy books. During the new kingdom of ancient Egypt, most Phoenicians were under Egyptian rule, and Phoenicians were deeply influenced by Egyptian culture.
In fact, before the Phoenician alphabet appeared, there were so-called primitive letters in Canaan or Sinai Peninsula, which were basically hieroglyphics of ancient Egypt. The Wikipedia page lists ten Egyptian symbols and the original Sinai alphabet, Phoenician alphabet, ancient Hebrew alphabet and Aramaic alphabet.
Before the Phoenician alphabet appeared, there were early letters in Canaan or Sinai Peninsula, which were basically holy book symbols in ancient Egypt. The Wikipedia page lists the correspondence between ten Egyptian symbols and the original Sinai alphabet, Phoenician alphabet, ancient Hebrew alphabet, Aramaic alphabet and Greek/Italian alphabet:
Phoenicia is an ancient civilization on the east coast of the Mediterranean, and its geographical position is roughly equivalent to the coastal areas of Lebanon and Syria today. "Phoenicia" is the Greek name of this area, which means "the country of purple" and is named after its rich purple dyes. The Romans called it "Punic".
About13rd century BC, Phoenicians created the first alphabet in human history, with ***22 letters (no vowels). This is the great contribution of Phoenicians to human culture. The Phoenician alphabet is the beginning of the world alphabet. In the west, it derived from ancient Greek letters and developed into Latin letters and Slavic letters. Greek letters and Latin letters are the basis of letters in all western countries. In the East, it derived Aramaic alphabet and evolved into national alphabet such as Hindi, Arabic, Hebrew and Persian. The Uyghur, Mongolian and Manchu letters in China also evolved from this.
1066 after the Norman conquest, many documents were French at that time. They abandoned some unfamiliar spelling rules, introduced some new rules from French, and made some new exceptions according to different situations. This made great changes in English spelling and words at that time. Some letters were abolished, others were transformed and gradually evolved into 26 letters of modern English.
Baidu encyclopedia-English letters