sigma Greek letter equivalent of s, written σ, commonly used to denote the standard deviation of a distribution or a set of data. The capital ∑ is used to denote the sum in the summation notation.
sigma
数学辞典收录了4151条数学词条，基本涵盖了常用数学知识及数学英语单词词组的翻译及用法，是数学学习的有利工具。