等とう比ひ級きゅう数すう

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Meanings

1

noun

geometric series

mathematics

Mathematical term for a series where each term is multiplied by a constant ratio. Used in algebra and calculus contexts.

等etc., and so forth, class (first)

比compare, race, ratio

級class, rank, grade

数number, strength, fate

等とう差さ数すう列れつ
等差数列 is an arithmetic sequence (constant difference), while 等比級数 is a geometric series (constant ratio).
等とう比ひ数すう列れつ
等比数列 is a geometric sequence (list of terms), while 等比級数 is the sum of those terms.

Compound of 等比 (geometric ratio) and 級数 (series). The term is a direct mathematical coinage from Chinese-character components.