几何级数 (jī) — geometric progression; geometric series

Definition

A math term for a sequence where each term is the previous one multiplied by a fixed ratio (e.g. 2, 4, 8, 16). Contrast with 算术级数 (arithmetic progression), which adds a fixed difference instead.

noun

geometric progressiongeometric series

Examples

几何级数，。
Zhè ge jī zēng zhǎng dé hěn kuài, měi gè shù shì qián yí gè shù de liǎng bèi.
This geometric progression grows very fast; each number is twice the previous one.
几何级数nS=a(1-r^n)/(1-r)。
Jì suàn jī qián n xiàng hé de gōng shì shì S=a (1-r^n) / (1-r).
The formula for the sum of the first n terms of a geometric series is S=a(1-r^n)/(1-r).
几何级数，。
jī Hé suàn shù jí shù bù yí yàng, tā shì àn gù dìng bǐ lì zēng jiā de.
Geometric progressions are different from arithmetic progressions; they increase by a fixed ratio.

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