求和符号
summation notation The symbol $\sum$ denotes summation, e.g., $\sum_{i=1}^{n} a_i$ means $a_1 + a_2 + \cdots + a_n$.
CSCA 数学 考试术语
summation notation The symbol $\sum$ denotes summation, e.g., $\sum_{i=1}^{n} a_i$ means $a_1 + a_2 + \cdots + a_n$.
CSCA 数学 考试术语