n
∑ai=a 1+a2+a3+...+ An.
i= 1
The following i= 1.
"I" means that I is a variable in the general term formula, which increases with the increase of the number of terms 1.
"1" means the change from i= 1,
The "n" above means adding to i=n,
"ai" is a general formula.
∞
∑ai=a 1+a2+a3+。 , ∞ means infinity, and the antecedent means the sum of infinite terms.
i= 1
Similar symbols are ∏ and ∏, that is, the capitalization of π is an orthogonal symbol, and the cumulative term is multiplied. The format is the same as ∑, with the starting value below and the ending value above, such as:
n
∏ai=a2*a3*a4*...* Ann
i=2