∑ formula calculation: the number indicating the beginning and end. For example, i=2 below, and the number 10 above means from 2 to 10.
For example, 10∑(2i+ 1) represents the summation formula: (2 * 2+1)+(2 * 3+1)+...+(2).
i=2
2i+ 1 in the formula is the general formula Ai of the series, I is the ordinal number of the item, i=2 means counting from the second item of the series {2i+ 1}, and the top 10 is the end of the item 10.
2. The usage of ∑:
Where I stands for the lower bound, n stands for the upper bound, and k starts from I and goes all the way to n, all of which add up.
∑ i can also be expressed as the sum of I, which is a variable.
The extended data capital σ is used for mathematical summation symbols, such as ∑Pi, where i= 1, 2, ..., t, which is the sum ...+angle of P 1+P2+. Lowercase σ is used for statistical standard deviation. Both the с of Cyrillic alphabet and the S of Latin alphabet are derived from Sigma.
∑ (summation symbol)
English name: Shima
Chinese name: Sigma (capital σ, lowercase σ)
Sigma (capital σ, lowercase σ) is the18th Greek letter. In Greek, if the last letter of a word is lowercase sigma, it should be written in lowercase sigma. In modern Greece, this number stands for 6.
Capital σ is used for mathematical summation symbols, such as ∑Pi, where i= 1, 2, ..., t, which is the sum of P 1+P2+ and ...+angle. Lowercase σ is used for statistical standard deviation. Both the с of Cyrillic alphabet and the S of Latin alphabet are derived from Sigma.
Baidu Encyclopedia-√