σ is the18th capital letter of the 24 letters in the Greek alphabet, pronounced as sigma (alto sigma) and lowercase as σ.

In mathematics, σ means sum. For example:

= 1+2+3+......+(n- 1)+n=n(n+ 1)/2

Read: sum I from 1 to n.

Extended data:

∑ (summation symbol)

English name: Shima

Chinese name: Sigma (capital σ, lowercase σ)

The eighteenth Greek letter. In Greek, if the last letter of a word is lowercase sigma, what should it be written as? This letter is also called final sigma(Unicode: U+03C2). In modern Greece, this number stands for 6.

Greek alphabet is a letter used in Greek, and it is also widely used in mathematics, physics, biology, chemistry, astronomy and other disciplines. Greek letters are similar to English letters and Russian letters, but with different symbols and the same phonetic properties.

Greek letters are the earliest letters with vowels in the world. Cyrillic letters and Georgian letters used in Russian and Ukrainian are all developed from Greek letters, so people who have studied Russian will feel deja vu when they use Greek letters.

Greek letters have entered the vocabulary of many languages. For example, the international word Delta comes from the Greek letter δ, because δ is a triangle.