๐Ÿ•ท๏ธ Crawler Inspector

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Raw Queries and Responses

1. Shard Calculation

Query:
Response:
Calculated Shard: 37 (from laksa053)

2. Crawled Status Check

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3. Robots.txt Check

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Response:

4. Spam/Ban Check

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5. Seen Status Check

โ„น๏ธ Skipped - page is already crawled

๐Ÿ“„
INDEXABLE
โœ…
CRAWLED
21 days ago
๐Ÿค–
ROBOTS ALLOWED

Page Info Filters

FilterStatusConditionDetails
HTTP statusPASSdownload_http_code = 200HTTP 200
Age cutoffPASSdownload_stamp > now() - 6 MONTH0.7 months ago
History dropPASSisNull(history_drop_reason)No drop reason
Spam/banPASSfh_dont_index != 1 AND ml_spam_score = 0ml_spam_score=0
CanonicalPASSmeta_canonical IS NULL OR = '' OR = src_unparsedNot set

Page Details

PropertyValue
URLhttps://ko.calc-site.com/progressions/geometric_sum
Last Crawled2026-03-20 18:56:23 (21 days ago)
First Indexed2022-08-27 09:34:36 (3 years ago)
HTTP Status Code200
Meta Title๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ - ์ˆ˜์—ด ๊ณ„์‚ฐ - ๊ณ„์‚ฐ ์‚ฌ์ดํŠธ
Meta Description์ง€์ •๋œ ์ดˆํ•ญ๊ณผ ๊ณต๋น„์™€ ๋ฒ”์œ„๋กœ๋ถ€ํ„ฐ ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ์„ ๊ณ„์‚ฐํ•ฉ๋‹ˆ๋‹ค.
Meta Canonicalnull
Boilerpipe Text
์ฒซํ•ญ๊ณผ ๊ณต๋น„๋กœ๋ถ€ํ„ฐ ๋“ฑ๋น„์ˆ˜์—ด์„ ๊ณ„์‚ฐํ•ด, ์ง€์ •๋œ ๋ฒ”์œ„์˜ ์ˆ˜์—ด์˜ ํ•ฉ์„ ํ‘œ์‹œํ•ฉ๋‹ˆ๋‹ค. ์ดˆํ•ญ๊ณผ ๊ณต๋น„์™€ ๊ณ„์‚ฐํ•˜๊ณ  ์‹ถ์€ ์ˆ˜์—ด์˜ ๋ฒ”์œ„๋ฅผ ์ž…๋ ฅํ•˜๊ณ  โ€œ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ๊ณ„ ๊ณ„์‚ฐโ€๋ฒ„ํŠผ์„ ํด๋ฆญํ•˜๋ฉด, ์ง€์ •๋œ ๋ฒ”์œ„์˜ ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ๊ณ„๋ฅผ ๊ณ„์‚ฐํ•ด ํ‘œ์‹œํ•ฉ๋‹ˆ๋‹ค. ๋˜ํ•œ ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ์„ ๊ตฌํ•˜๋Š” ๊ณ„์‚ฐ ๋ฐฉ๋ฒ•๋„ ํ‘œ์‹œํ•ฉ๋‹ˆ๋‹ค. ์ดˆํ•ญ๊ณผ ๊ณต๋น„์€ 15์ž๋ฆฌ๊นŒ์ง€, n๋ฒˆ์งธ ์ˆ˜์€ 10,000๊นŒ์ง€ ์ž…๋ ฅํ•˜์„ธ์š”. ๋“ฑ๋น„์ˆ˜์—ด์ด๋ž€, ์ธ์ ‘ํ•˜๋Š” ๊ฐ๊ฐ์˜ ํ•ญ์˜ ๋น„์œจ์ด ๋™์ผํ•œ ์ˆ˜์—ด์„ ๋งํ•ฉ๋‹ˆ๋‹ค. ์ˆ˜์—ด์˜ ์ฒ˜์Œ ํ•ญ์„ ์ดˆํ•ญ์ด๋ผ๊ณ  ํ•˜๋ฉฐ, ๊ฐ๊ฐ์˜ ์ธ์ ‘ ํ•ญ์˜ ๋น„์œจ์„ ๊ณต๋น„๋ผ๊ณ  ํ•ฉ๋‹ˆ๋‹ค. ์˜ˆ๋ฅผ ๋“ค์–ด, ๋‹ค์Œ๊ณผ ๊ฐ™์€ ์ˆ˜์—ด์€ ์ฒซํ•ญ์ด 1์ด๊ณ  ๊ณต๋น„๊ฐ€ 3์ธ ์ˆ˜์—ด์ด ๋ฉ๋‹ˆ๋‹ค. ๊ณต๋น„๊ฐ€ 3์ด๋ฏ€๋กœ, ์ธ์ ‘ํ•˜๋Š” ํ•ญ์˜ ๋น„๋Š” ๋ชจ๋‘ โ€œ1:3โ€์ด ๋˜์–ด ์žˆ์Šต๋‹ˆ๋‹ค. 1, 3, 9, 27, 81, 243, 729... ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ์„ ๊ณ„์‚ฐํ•ฉ๋‹ˆ๋‹ค. ์ฒซํ•ญ์„ a ๊ณต๋น„๋ฅผ r๋กœ ํ•˜๋ฉด, ์ˆ˜์—ด์€ ์ดํ•˜์™€ ๊ฐ™์ด ๋ฉ๋‹ˆ๋‹ค. a, ar, ar 2 , ar 3 ... ar nโˆ’2 , ar nโˆ’1 ์ด ์ˆ˜์—ด์˜ ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ์„ Sn์œผ๋กœ ํ•˜๋ฉด, Sn์€ ๋‹ค์Œ๊ณผ ๊ฐ™์ด ๋‚˜ํƒ€๋‚ผ ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค. S n = a + ar + ar 2 + ar 3 + ... + ar nโˆ’2 + ar nโˆ’1 ์ด ๋ฐฉ์ •์‹์˜ ์–‘์ชฝ์— r์„ ๊ณฑํ•ฉ๋‹ˆ๋‹ค. rS n = ar + ar 2 + ar 3 + ar 4 + ... + ar nโˆ’1 + ar n ์ด ๋‘ ํ‘œํ˜„์‹์˜ ์™ผ์ชฝ๊ณผ ์˜ค๋ฅธ์ชฝ์„ ๊ฐ๊ฐ ๋บ๋‹ˆ๋‹ค. ย  S n = a + ar + ar 2 + ... + ar nโˆ’2 + ar nโˆ’1 ย  ย  โˆ’ rS n = ย  ย  ar + ar 2 + ... + ar nโˆ’2 + ar nโˆ’1 + ar n ย  S n โˆ’ rS n = a โˆ’ ar n ์ขŒ๋ณ€์€ S n - rS n ๊ฐ€ ๋˜๊ณ , ์šฐ๋ณ€์€ ๋„์ค‘์˜ ๋ถ€๋ถ„์ด ๋ชจ๋‘ ์‚ฌ๋ผ์ง€๋ฏ€๋กœ, a - ar n ๊ฐ€ ๋ฉ๋‹ˆ๋‹ค. S n โˆ’ rS n = a โˆ’ ar n ์ด๊ฒƒ์„ Sn์— ๋Œ€ํ•ด ํ•ด๊ฒฐํ•ฉ๋‹ˆ๋‹ค. S n (1 โˆ’ r) = a(1 โˆ’ r n ) S n = a(1 โˆ’ r n ) (1 โˆ’ r) ๋”ฐ๋ผ์„œ S n = a(1 โˆ’ r n ) (1 โˆ’ r) (r โ‰  1) ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ = ์ดˆํ•ญ ร— (1 โˆ’ ๊ณต๋น„ n ) (1 โˆ’ ๊ณต๋น„) r = 1 ์ผ ๋•Œ ๋“ฑ๋น„์ˆ˜์—ด์˜ ์ˆ˜๋Š” ๋ชจ๋‘ ์ฒซ ํ•ญ๊ณผ ๋™์ผํ•˜๋ฏ€๋กœ ๋‹ค์Œ๊ณผ ๊ฐ™์Šต๋‹ˆ๋‹ค. S n = a + a + a + ... + a + a = na ๋”ฐ๋ผ์„œ S n = na (r = 1) ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ = n ร— ์ดˆํ•ญ n๋ฒˆ์งธ์—์„œ m๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ n๋ฒˆ์งธ์—์„œ m๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ์„ ๊ณ„์‚ฐํ•˜๋Š” ๊ฒฝ์šฐ๋„ ๋งˆ์ฐฌ๊ฐ€์ง€๋กœ ์ˆ˜์—ด์„ ๋ฐ˜๋Œ€๋กœ ํ•˜์—ฌ ์–‘๋ณ€์„ ๋”ํ•ฉ๋‹ˆ๋‹ค. ย  S mโˆ’n = ar nโˆ’1 + ar n + ar n+1 + ... + ar mโˆ’2 + ar mโˆ’1 ย  ย  โˆ’ rS mโˆ’n = ย  ย  ar n + ar n+1 + ... + ar mโˆ’2 + ar mโˆ’1 + ar m ย  S mโˆ’n โˆ’ rS mโˆ’n = ar nโˆ’1 โˆ’ ar m ์ขŒ๋ณ€์€ rS m-n -S m-n ๊ฐ€ ๋˜๊ณ , ์šฐ๋ณ€์€ ๋„์ค‘์˜ ๋ถ€๋ถ„์ด ๋ชจ๋‘ ์‚ฌ๋ผ์ง€๋ฏ€๋กœ, ar n-1 โˆ’ ar m ์ž…๋‹ˆ๋‹ค. rS mโˆ’n โˆ’ S mโˆ’n = ar nโˆ’1 โˆ’ ar m ์ด๊ฒƒ์„ S m-n ์— ๋Œ€ํ•ด ํ’€์–ด ๋ด…์‹œ๋‹ค. S mโˆ’n (1 โˆ’ r) = a(r nโˆ’1 โˆ’ r m ) S mโˆ’n = a(r nโˆ’1 โˆ’ r m ) (1 โˆ’ r) ๋”ฐ๋ผ์„œ S mโˆ’n = a(r nโˆ’1 โˆ’ r m ) (1 โˆ’ r) (r โ‰  1) n๋ฒˆ์งธ์—์„œ m๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ = ์ดˆํ•ญ ร— (๊ณต๋น„ nโˆ’1 โˆ’ ๊ณต๋น„ m ) (1 โˆ’ ๊ณต๋น„) r = 1 ์ผ ๋•Œ ๋“ฑ๋น„์ˆ˜์—ด์˜ ์ˆ˜๋Š” ๋ชจ๋‘ ์ฒซ ํ•ญ๊ณผ ๋™์ผํ•˜๋ฏ€๋กœ ๋‹ค์Œ๊ณผ ๊ฐ™์Šต๋‹ˆ๋‹ค. S mโˆ’n = a + a + a + ... + a + a = (m โˆ’ n + 1)a ๋”ฐ๋ผ์„œ S mโˆ’n = (m โˆ’ n + 1)a (r = 1) ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ = (m โˆ’ n + 1) ร— ์ดˆํ•ญ
Markdown
[![๊ณ„์‚ฐ ์‚ฌ์ดํŠธ](https://ko.calc-site.com/img/logo_ko.jpg)](https://ko.calc-site.com/) [Sitemap](https://ko.calc-site.com/sitemaps) # ์ง€์ •๋œ ์ดˆํ•ญ๊ณผ ๊ณต๋น„์™€ ๋ฒ”์œ„๋กœ๋ถ€ํ„ฐ ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ์„ ๊ณ„์‚ฐํ•ฉ๋‹ˆ๋‹ค. ## ์ฒซํ•ญ๊ณผ ๊ณต๋น„์™€ ๋ฒ”์œ„๋ฅผ ์ž…๋ ฅํ•˜์—ฌ ์ง€์ •๋œ ๋ฒ”์œ„์˜ ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ์„ ๊ณ„์‚ฐํ•˜์—ฌ ํ‘œ์‹œํ•ฉ๋‹ˆ๋‹ค. - [์ƒ๋‹จ](https://ko.calc-site.com/) - [์˜ค๋Š˜์˜ ๋‹ฌ๋ ฅ](https://ko.calc-site.com/search_dates/3/21/2026) - [์‹œ๊ฐ„ ๊ณ„์‚ฐ](https://ko.calc-site.com/times) - [๋‚ ์งœ ๊ณ„์‚ฐ](https://ko.calc-site.com/dates) - [๋‹ฌ๋ ฅ ๊ณ„์‚ฐ](https://ko.calc-site.com/calendars) - [ํ™•๋ฅ  ๊ณ„์‚ฐ](https://ko.calc-site.com/probabilities) - [๋‹จ์œ„ ๋ณ€ํ™˜](https://ko.calc-site.com/units) - [๋‚œ์ˆ˜ ๊ณ„์‚ฐ](https://ko.calc-site.com/randoms) - [๋ฉด์  ๊ณ„์‚ฐ](https://ko.calc-site.com/areas) ![๋‹ฌ๋ ฅ](https://ko.calc-site.com/img/left_title02_ko.jpg) | | | | | | | | |---|---|---|---|---|---|---| | | | | | | | | | [\<\<]() | [\<]() | 2026๋…„3์›” | [\>]() | [\>\>]() | | | | ์ผ | ์›” | ํ™” | ์ˆ˜ | ๋ชฉ | ๊ธˆ | ํ†  | | [1](https://ko.calc-site.com/search_dates/3/1/2026) | [2](https://ko.calc-site.com/search_dates/3/2/2026) | [3](https://ko.calc-site.com/search_dates/3/3/2026) | [4](https://ko.calc-site.com/search_dates/3/4/2026) | [5](https://ko.calc-site.com/search_dates/3/5/2026) | [6](https://ko.calc-site.com/search_dates/3/6/2026) | [7](https://ko.calc-site.com/search_dates/3/7/2026) | | [8](https://ko.calc-site.com/search_dates/3/8/2026) | [9](https://ko.calc-site.com/search_dates/3/9/2026) | [10](https://ko.calc-site.com/search_dates/3/10/2026) | [11](https://ko.calc-site.com/search_dates/3/11/2026) | [12](https://ko.calc-site.com/search_dates/3/12/2026) | [13](https://ko.calc-site.com/search_dates/3/13/2026) | [14](https://ko.calc-site.com/search_dates/3/14/2026) | | [15](https://ko.calc-site.com/search_dates/3/15/2026) | [16](https://ko.calc-site.com/search_dates/3/16/2026) | [17](https://ko.calc-site.com/search_dates/3/17/2026) | [18](https://ko.calc-site.com/search_dates/3/18/2026) | [19](https://ko.calc-site.com/search_dates/3/19/2026) | [20](https://ko.calc-site.com/search_dates/3/20/2026) | [21](https://ko.calc-site.com/search_dates/3/21/2026) | | [22](https://ko.calc-site.com/search_dates/3/22/2026) | [23](https://ko.calc-site.com/search_dates/3/23/2026) | [24](https://ko.calc-site.com/search_dates/3/24/2026) | [25](https://ko.calc-site.com/search_dates/3/25/2026) | [26](https://ko.calc-site.com/search_dates/3/26/2026) | [27](https://ko.calc-site.com/search_dates/3/27/2026) | [28](https://ko.calc-site.com/search_dates/3/28/2026) | | [29](https://ko.calc-site.com/search_dates/3/29/2026) | [30](https://ko.calc-site.com/search_dates/3/30/2026) | [31](https://ko.calc-site.com/search_dates/3/31/2026) | [1](https://ko.calc-site.com/search_dates/4/1/2026) | [2](https://ko.calc-site.com/search_dates/4/2/2026) | [3](https://ko.calc-site.com/search_dates/4/3/2026) | [4](https://ko.calc-site.com/search_dates/4/4/2026) | ![๊ณ„์‚ฐ ์‚ฌ์ดํŠธ ์ฝ˜ํ…์ธ ](https://ko.calc-site.com/img/left_title03_ko.jpg) - [![์‹œ๊ฐ„ ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/time.png)์‹œ๊ฐ„ ๊ณ„์‚ฐ](https://ko.calc-site.com/times) - [![๋‚ ์งœ ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/date.png)๋‚ ์งœ ๊ณ„์‚ฐ](https://ko.calc-site.com/dates) - [![๋‹ฌ๋ ฅ ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/calendar.png)๋‹ฌ๋ ฅ ๊ณ„์‚ฐ](https://ko.calc-site.com/calendars) - [![๊ฑด๊ฐ• ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/health.png)๊ฑด๊ฐ• ๊ณ„์‚ฐ](https://ko.calc-site.com/healths) - [![๋ˆ ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/money.png)๋ˆ ๊ณ„์‚ฐ](https://ko.calc-site.com/monies) - [![๋ฐ”์ด์˜ค ๋ฆฌ๋“ฌ ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/biorhythm.png)๋ฐ”์ด์˜ค ๋ฆฌ๋“ฌ ๊ณ„์‚ฐ](https://ko.calc-site.com/biorhythms) - [![๋ฌธ์ž ๋ณ€ํ™˜](https://ko.calc-site.com/img/icon/letter.png)๋ฌธ์ž ๋ณ€ํ™˜](https://ko.calc-site.com/letters) - [![๋‹จ์œ„ ๋ณ€ํ™˜](https://ko.calc-site.com/img/icon/unit.png)๋‹จ์œ„ ๋ณ€ํ™˜](https://ko.calc-site.com/units) - [![ํ‰๊ท  ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/average.png)ํ‰๊ท  ๊ณ„์‚ฐ](https://ko.calc-site.com/averages) - [![์†๋„ ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/speed.png)์†๋„ ๊ณ„์‚ฐ](https://ko.calc-site.com/speeds) - [![์ง€๋„ ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/map.png)์ง€๋„ ๊ณ„์‚ฐ](https://ko.calc-site.com/maps) - [![๋‚œ์ˆ˜ ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/random.png)๋‚œ์ˆ˜ ๊ณ„์‚ฐ](https://ko.calc-site.com/randoms) - [![์ˆœ์—ดยท์กฐํ•ฉ ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/permutations_combinations.png)์ˆœ์—ดยท์กฐํ•ฉ ๊ณ„์‚ฐ](https://ko.calc-site.com/permutations_combinations) - [![ํ™•๋ฅ  ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/probability.png)ํ™•๋ฅ  ๊ณ„์‚ฐ](https://ko.calc-site.com/probabilities) - [![๋ฉด์  ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/area.png)๋ฉด์  ๊ณ„์‚ฐ](https://ko.calc-site.com/areas) - [![๋ถ€ํ”ผ ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/volume.png)๋ถ€ํ”ผ ๊ณ„์‚ฐ](https://ko.calc-site.com/volumes) - [![์‚ผ๊ฐํ˜• ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/triangle.png)์‚ผ๊ฐํ˜• ๊ณ„์‚ฐ](https://ko.calc-site.com/triangles) - [![์†Œ์ˆ˜ยท๋ถ„์ˆ˜ ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/fraction.png)์†Œ์ˆ˜ยท๋ถ„์ˆ˜ ๊ณ„์‚ฐ](https://ko.calc-site.com/fractions) - [![์•ฝ์ˆ˜ยท๋ฐฐ์ˆ˜์˜ ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/divisor.png)์•ฝ์ˆ˜ยท๋ฐฐ์ˆ˜์˜ ๊ณ„์‚ฐ](https://ko.calc-site.com/divisors) - [![๋น„์œจ ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/ratio.png)๋น„์œจ ๊ณ„์‚ฐ](https://ko.calc-site.com/ratios) - [![์ˆ˜์—ด ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/progression.png)์ˆ˜์—ด ๊ณ„์‚ฐ](https://ko.calc-site.com/progressions) - [![์ง„์ˆ˜ ๋ณ€ํ™˜](https://ko.calc-site.com/img/icon/base.png)์ง„์ˆ˜ ๋ณ€ํ™˜](https://ko.calc-site.com/bases) - Information - [๊ฐœ์ธ ์ •๋ณด ๋ณดํ˜ธ ์ •์ฑ…](https://ko.calc-site.com/informations/privacy) - [๋ฉด์ฑ…์‚ฌํ•ญ](https://ko.calc-site.com/informations/disclaimer) - [๋ฌธ์˜](https://ko.calc-site.com/contacts) ![์‚ฌ์ดํŠธ ๋‚ด ๊ฒ€์ƒ‰](https://ko.calc-site.com/img/left_title04_ko.jpg) - [ํ†ฑ ํŽ˜์ด์ง€](https://ko.calc-site.com/) - [์ˆ˜์—ด ๊ณ„์‚ฐ](https://ko.calc-site.com/progressions) - ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ ## ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ ์ฒซํ•ญ๊ณผ ๊ณต๋น„๋กœ๋ถ€ํ„ฐ ๋“ฑ๋น„์ˆ˜์—ด์„ ๊ณ„์‚ฐํ•ด, ์ง€์ •๋œ ๋ฒ”์œ„์˜ ์ˆ˜์—ด์˜ ํ•ฉ์„ ํ‘œ์‹œํ•ฉ๋‹ˆ๋‹ค. ## ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ ๊ณ„์‚ฐ ์ •๋ณด ์ดˆํ•ญ๊ณผ ๊ณต๋น„์™€ ๊ณ„์‚ฐํ•˜๊ณ  ์‹ถ์€ ์ˆ˜์—ด์˜ ๋ฒ”์œ„๋ฅผ ์ž…๋ ฅํ•˜๊ณ  โ€œ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ๊ณ„ ๊ณ„์‚ฐโ€๋ฒ„ํŠผ์„ ํด๋ฆญํ•˜๋ฉด, ์ง€์ •๋œ ๋ฒ”์œ„์˜ ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ๊ณ„๋ฅผ ๊ณ„์‚ฐํ•ด ํ‘œ์‹œํ•ฉ๋‹ˆ๋‹ค. ๋˜ํ•œ ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ์„ ๊ตฌํ•˜๋Š” ๊ณ„์‚ฐ ๋ฐฉ๋ฒ•๋„ ํ‘œ์‹œํ•ฉ๋‹ˆ๋‹ค. ์ดˆํ•ญ๊ณผ ๊ณต๋น„์€ 15์ž๋ฆฌ๊นŒ์ง€, n๋ฒˆ์งธ ์ˆ˜์€ 10,000๊นŒ์ง€ ์ž…๋ ฅํ•˜์„ธ์š”. ## ๋“ฑ๋น„์ˆ˜์—ด์ด๋ž€? ๋“ฑ๋น„์ˆ˜์—ด์ด๋ž€, ์ธ์ ‘ํ•˜๋Š” ๊ฐ๊ฐ์˜ ํ•ญ์˜ ๋น„์œจ์ด ๋™์ผํ•œ ์ˆ˜์—ด์„ ๋งํ•ฉ๋‹ˆ๋‹ค. ์ˆ˜์—ด์˜ ์ฒ˜์Œ ํ•ญ์„ ์ดˆํ•ญ์ด๋ผ๊ณ  ํ•˜๋ฉฐ, ๊ฐ๊ฐ์˜ ์ธ์ ‘ ํ•ญ์˜ ๋น„์œจ์„ ๊ณต๋น„๋ผ๊ณ  ํ•ฉ๋‹ˆ๋‹ค. ์˜ˆ๋ฅผ ๋“ค์–ด, ๋‹ค์Œ๊ณผ ๊ฐ™์€ ์ˆ˜์—ด์€ ์ฒซํ•ญ์ด 1์ด๊ณ  ๊ณต๋น„๊ฐ€ 3์ธ ์ˆ˜์—ด์ด ๋ฉ๋‹ˆ๋‹ค. ๊ณต๋น„๊ฐ€ 3์ด๋ฏ€๋กœ, ์ธ์ ‘ํ•˜๋Š” ํ•ญ์˜ ๋น„๋Š” ๋ชจ๋‘ โ€œ1:3โ€์ด ๋˜์–ด ์žˆ์Šต๋‹ˆ๋‹ค. 1, 3, 9, 27, 81, 243, 729... ## ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ ๊ณ„์‚ฐ ๋ฐฉ๋ฒ• ### ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ์„ ๊ณ„์‚ฐํ•ฉ๋‹ˆ๋‹ค. ์ฒซํ•ญ์„ a ๊ณต๋น„๋ฅผ r๋กœ ํ•˜๋ฉด, ์ˆ˜์—ด์€ ์ดํ•˜์™€ ๊ฐ™์ด ๋ฉ๋‹ˆ๋‹ค. a, ar, ar2, ar3 ... arnโˆ’2, arnโˆ’1 ์ด ์ˆ˜์—ด์˜ ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ์„ Sn์œผ๋กœ ํ•˜๋ฉด, Sn์€ ๋‹ค์Œ๊ณผ ๊ฐ™์ด ๋‚˜ํƒ€๋‚ผ ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค. Sn = a + ar + ar2 + ar3 + ... + arnโˆ’2 + arnโˆ’1 ์ด ๋ฐฉ์ •์‹์˜ ์–‘์ชฝ์— r์„ ๊ณฑํ•ฉ๋‹ˆ๋‹ค. rSn = ar + ar2 + ar3 + ar4 + ... + arnโˆ’1 + arn ์ด ๋‘ ํ‘œํ˜„์‹์˜ ์™ผ์ชฝ๊ณผ ์˜ค๋ฅธ์ชฝ์„ ๊ฐ๊ฐ ๋บ๋‹ˆ๋‹ค. | | | | | | | | | | | | | | | |---|---|---|---|---|---|---|---|---|---|---|---|---|---| | | Sn | \= | a | \+ | ar | \+ | ar2 | \+ ... + | arnโˆ’2 | \+ | arnโˆ’1 | | | | โˆ’ | rSn | \= | | | ar | \+ | ar2 | \+ ... + | arnโˆ’2 | \+ | arnโˆ’1 | \+ | arn | | | Sn โˆ’ rSn | \= | a โˆ’ arn | | | | | | | | | | | ์ขŒ๋ณ€์€ Sn - rSn๊ฐ€ ๋˜๊ณ , ์šฐ๋ณ€์€ ๋„์ค‘์˜ ๋ถ€๋ถ„์ด ๋ชจ๋‘ ์‚ฌ๋ผ์ง€๋ฏ€๋กœ, a - arn๊ฐ€ ๋ฉ๋‹ˆ๋‹ค. Sn โˆ’ rSn = a โˆ’ arn ์ด๊ฒƒ์„ Sn์— ๋Œ€ํ•ด ํ•ด๊ฒฐํ•ฉ๋‹ˆ๋‹ค. Sn(1 โˆ’ r) = a(1 โˆ’ rn) Sn = a(1 โˆ’ rn)(1 โˆ’ r) ๋”ฐ๋ผ์„œ Sn\= a(1 โˆ’ rn)(1 โˆ’ r) (r โ‰  1) ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ = ์ดˆํ•ญ ร— (1 โˆ’ ๊ณต๋น„n)(1 โˆ’ ๊ณต๋น„) r = 1 ์ผ ๋•Œ ๋“ฑ๋น„์ˆ˜์—ด์˜ ์ˆ˜๋Š” ๋ชจ๋‘ ์ฒซ ํ•ญ๊ณผ ๋™์ผํ•˜๋ฏ€๋กœ ๋‹ค์Œ๊ณผ ๊ฐ™์Šต๋‹ˆ๋‹ค. Sn\= a + a + a + ... + a + a = na ๋”ฐ๋ผ์„œ Sn = na (r = 1) ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ = n ร— ์ดˆํ•ญ ### n๋ฒˆ์งธ์—์„œ m๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ n๋ฒˆ์งธ์—์„œ m๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ์„ ๊ณ„์‚ฐํ•˜๋Š” ๊ฒฝ์šฐ๋„ ๋งˆ์ฐฌ๊ฐ€์ง€๋กœ ์ˆ˜์—ด์„ ๋ฐ˜๋Œ€๋กœ ํ•˜์—ฌ ์–‘๋ณ€์„ ๋”ํ•ฉ๋‹ˆ๋‹ค. | | | | | | | | | | | | | | | |---|---|---|---|---|---|---|---|---|---|---|---|---|---| | | Smโˆ’n | \= | arnโˆ’1 | \+ | arn | \+ | arn+1 | \+ ... + | armโˆ’2 | \+ | armโˆ’1 | | | | โˆ’ | rSmโˆ’n | \= | | | arn | \+ | arn+1 | \+ ... + | armโˆ’2 | \+ | armโˆ’1 | \+ | arm | | | Smโˆ’n โˆ’ rSmโˆ’n | \= | arnโˆ’1 โˆ’ arm | | | | | | | | | | | ์ขŒ๋ณ€์€ rSm-n -Sm-n๊ฐ€ ๋˜๊ณ , ์šฐ๋ณ€์€ ๋„์ค‘์˜ ๋ถ€๋ถ„์ด ๋ชจ๋‘ ์‚ฌ๋ผ์ง€๋ฏ€๋กœ, arn-1 โˆ’ arm์ž…๋‹ˆ๋‹ค. rSmโˆ’n โˆ’ Smโˆ’n = arnโˆ’1 โˆ’ arm ์ด๊ฒƒ์„ Sm-n์— ๋Œ€ํ•ด ํ’€์–ด ๋ด…์‹œ๋‹ค. Smโˆ’n(1 โˆ’ r) = a(rnโˆ’1 โˆ’ rm) Smโˆ’n\= a(rnโˆ’1 โˆ’ rm)(1 โˆ’ r) ๋”ฐ๋ผ์„œ Smโˆ’n\= a(rnโˆ’1 โˆ’ rm)(1 โˆ’ r) (r โ‰  1) n๋ฒˆ์งธ์—์„œ m๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ = ์ดˆํ•ญ ร— (๊ณต๋น„nโˆ’1 โˆ’ ๊ณต๋น„m)(1 โˆ’ ๊ณต๋น„) r = 1 ์ผ ๋•Œ ๋“ฑ๋น„์ˆ˜์—ด์˜ ์ˆ˜๋Š” ๋ชจ๋‘ ์ฒซ ํ•ญ๊ณผ ๋™์ผํ•˜๋ฏ€๋กœ ๋‹ค์Œ๊ณผ ๊ฐ™์Šต๋‹ˆ๋‹ค. Smโˆ’n\= a + a + a + ... + a + a = (m โˆ’ n + 1)a ๋”ฐ๋ผ์„œ Smโˆ’n = (m โˆ’ n + 1)a (r = 1) ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ = (m โˆ’ n + 1) ร— ์ดˆํ•ญ [์ˆ˜์—ด ๊ณ„์‚ฐ](https://ko.calc-site.com/progressions) - ยท[๋“ฑ์ฐจ์ˆ˜์—ด](https://ko.calc-site.com/progressions/arithmetic) - ยท[๋“ฑ์ฐจ์ˆ˜์—ด์˜ ํ•ฉ](https://ko.calc-site.com/progressions/arithmetic_sum) - ยท[๋“ฑ๋น„์ˆ˜์—ด](https://ko.calc-site.com/progressions/geometric) - ยท[๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ](https://ko.calc-site.com/progressions/geometric_sum) - ยท[ํ”ผ๋ณด๋‚˜์น˜ ์ˆ˜์—ด](https://ko.calc-site.com/progressions/fibonacci) - ยท[์ˆ˜์—ด์˜ ํ•ฉ (pa^2+qa+r)](https://ko.calc-site.com/progressions/difference_sum) [์ด ํŽ˜์ด์ง€์˜ ๋งจ ์œ„๋กœ ๋Œ์•„๊ฐ€๊ธฐ](https://ko.calc-site.com/progressions/geometric_sum#header) ### ![์ˆ˜์—ด ๊ณ„์‚ฐ](https://ko.calc-site.com/img/icon/progression.png)์ˆ˜์—ด ๊ณ„์‚ฐ - [๋“ฑ์ฐจ์ˆ˜์—ด](https://ko.calc-site.com/progressions/arithmetic) - [๋“ฑ์ฐจ์ˆ˜์—ด์˜ ํ•ฉ](https://ko.calc-site.com/progressions/arithmetic_sum) - [๋“ฑ๋น„์ˆ˜์—ด](https://ko.calc-site.com/progressions/geometric) - ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ - [ํ”ผ๋ณด๋‚˜์น˜ ์ˆ˜์—ด](https://ko.calc-site.com/progressions/fibonacci) - [์ˆ˜์—ด์˜ ํ•ฉ (pa^2+qa+r)](https://ko.calc-site.com/progressions/difference_sum) ### ![๊ณ„์‚ฐ๊ธฐ](https://ko.calc-site.com/img/icon/calculator.png)๊ฐ„๋‹จํ•œ ๊ณ„์‚ฐ๊ธฐ ๊ฒฐ๊ณผ๋ฅผ ์ž„์‹œ ์ €์žฅ ### ![์ธ๊ธฐ ํŽ˜์ด์ง€](https://ko.calc-site.com/img/icon/popular.png)์ธ๊ธฐ ํŽ˜์ด์ง€ - 1\. [๋‚œ์ˆ˜ ์ƒ์„ฑ](https://ko.calc-site.com/randoms/integral) - 2\. [์‹œ๊ฐ„ ๋ณ€ํ™˜](https://ko.calc-site.com/times/time_convert) - 3\. [๋‚ ์งœ ๊ณ„์‚ฐ](https://ko.calc-site.com/dates/calc_date) - 4\. [์ „๊ฐโ‡”๋ฐ˜๊ฐ์œผ๋กœ ๋ณ€ํ™˜](https://ko.calc-site.com/letters/convert_full_half) - 5\. [ํž˜ ๋ณ€ํ™˜](https://ko.calc-site.com/units/force) - 6\. [๋‹จ์œ„ ๋ณ€ํ™˜](https://ko.calc-site.com/units) - 7\. [๋ฉด์  ๋ณ€ํ™˜](https://ko.calc-site.com/units/area) - 8\. [๋Œ€๋ฌธ์ž โ‡” ์†Œ๋ฌธ์ž๋กœ ๋ณ€ํ™˜](https://ko.calc-site.com/letters/convert_case) - 9\. [์—ฐ์†์œผ๋กœ ๋งž์„ ํ™•๋ฅ ](https://ko.calc-site.com/probabilities/continuous_win) - 10\. 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์ฒซํ•ญ๊ณผ ๊ณต๋น„๋กœ๋ถ€ํ„ฐ ๋“ฑ๋น„์ˆ˜์—ด์„ ๊ณ„์‚ฐํ•ด, ์ง€์ •๋œ ๋ฒ”์œ„์˜ ์ˆ˜์—ด์˜ ํ•ฉ์„ ํ‘œ์‹œํ•ฉ๋‹ˆ๋‹ค. ์ดˆํ•ญ๊ณผ ๊ณต๋น„์™€ ๊ณ„์‚ฐํ•˜๊ณ  ์‹ถ์€ ์ˆ˜์—ด์˜ ๋ฒ”์œ„๋ฅผ ์ž…๋ ฅํ•˜๊ณ  โ€œ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ๊ณ„ ๊ณ„์‚ฐโ€๋ฒ„ํŠผ์„ ํด๋ฆญํ•˜๋ฉด, ์ง€์ •๋œ ๋ฒ”์œ„์˜ ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ๊ณ„๋ฅผ ๊ณ„์‚ฐํ•ด ํ‘œ์‹œํ•ฉ๋‹ˆ๋‹ค. ๋˜ํ•œ ๋“ฑ๋น„์ˆ˜์—ด์˜ ํ•ฉ์„ ๊ตฌํ•˜๋Š” ๊ณ„์‚ฐ ๋ฐฉ๋ฒ•๋„ ํ‘œ์‹œํ•ฉ๋‹ˆ๋‹ค. ์ดˆํ•ญ๊ณผ ๊ณต๋น„์€ 15์ž๋ฆฌ๊นŒ์ง€, n๋ฒˆ์งธ ์ˆ˜์€ 10,000๊นŒ์ง€ ์ž…๋ ฅํ•˜์„ธ์š”. ๋“ฑ๋น„์ˆ˜์—ด์ด๋ž€, ์ธ์ ‘ํ•˜๋Š” ๊ฐ๊ฐ์˜ ํ•ญ์˜ ๋น„์œจ์ด ๋™์ผํ•œ ์ˆ˜์—ด์„ ๋งํ•ฉ๋‹ˆ๋‹ค. ์ˆ˜์—ด์˜ ์ฒ˜์Œ ํ•ญ์„ ์ดˆํ•ญ์ด๋ผ๊ณ  ํ•˜๋ฉฐ, ๊ฐ๊ฐ์˜ ์ธ์ ‘ ํ•ญ์˜ ๋น„์œจ์„ ๊ณต๋น„๋ผ๊ณ  ํ•ฉ๋‹ˆ๋‹ค. ์˜ˆ๋ฅผ ๋“ค์–ด, ๋‹ค์Œ๊ณผ ๊ฐ™์€ ์ˆ˜์—ด์€ ์ฒซํ•ญ์ด 1์ด๊ณ  ๊ณต๋น„๊ฐ€ 3์ธ ์ˆ˜์—ด์ด ๋ฉ๋‹ˆ๋‹ค. ๊ณต๋น„๊ฐ€ 3์ด๋ฏ€๋กœ, ์ธ์ ‘ํ•˜๋Š” ํ•ญ์˜ ๋น„๋Š” ๋ชจ๋‘ โ€œ1:3โ€์ด ๋˜์–ด ์žˆ์Šต๋‹ˆ๋‹ค. 1, 3, 9, 27, 81, 243, 729... ### ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ์„ ๊ณ„์‚ฐํ•ฉ๋‹ˆ๋‹ค. ์ฒซํ•ญ์„ a ๊ณต๋น„๋ฅผ r๋กœ ํ•˜๋ฉด, ์ˆ˜์—ด์€ ์ดํ•˜์™€ ๊ฐ™์ด ๋ฉ๋‹ˆ๋‹ค. a, ar, ar2, ar3 ... arnโˆ’2, arnโˆ’1 ์ด ์ˆ˜์—ด์˜ ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ์„ Sn์œผ๋กœ ํ•˜๋ฉด, Sn์€ ๋‹ค์Œ๊ณผ ๊ฐ™์ด ๋‚˜ํƒ€๋‚ผ ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค. Sn = a + ar + ar2 + ar3 + ... + arnโˆ’2 + arnโˆ’1 ์ด ๋ฐฉ์ •์‹์˜ ์–‘์ชฝ์— r์„ ๊ณฑํ•ฉ๋‹ˆ๋‹ค. rSn = ar + ar2 + ar3 + ar4 + ... + arnโˆ’1 + arn ์ด ๋‘ ํ‘œํ˜„์‹์˜ ์™ผ์ชฝ๊ณผ ์˜ค๋ฅธ์ชฝ์„ ๊ฐ๊ฐ ๋บ๋‹ˆ๋‹ค. | | | | | | | | | | | | | | | |---|---|---|---|---|---|---|---|---|---|---|---|---|---| | | Sn | \= | a | \+ | ar | \+ | ar2 | \+ ... + | arnโˆ’2 | \+ | arnโˆ’1 | | | | โˆ’ | rSn | \= | | | ar | \+ | ar2 | \+ ... + | arnโˆ’2 | \+ | arnโˆ’1 | \+ | arn | | | Sn โˆ’ rSn | \= | a โˆ’ arn | | | | | | | | | | | ์ขŒ๋ณ€์€ Sn - rSn๊ฐ€ ๋˜๊ณ , ์šฐ๋ณ€์€ ๋„์ค‘์˜ ๋ถ€๋ถ„์ด ๋ชจ๋‘ ์‚ฌ๋ผ์ง€๋ฏ€๋กœ, a - arn๊ฐ€ ๋ฉ๋‹ˆ๋‹ค. Sn โˆ’ rSn = a โˆ’ arn ์ด๊ฒƒ์„ Sn์— ๋Œ€ํ•ด ํ•ด๊ฒฐํ•ฉ๋‹ˆ๋‹ค. Sn(1 โˆ’ r) = a(1 โˆ’ rn) Sn = a(1 โˆ’ rn)(1 โˆ’ r) ๋”ฐ๋ผ์„œ Sn\= a(1 โˆ’ rn)(1 โˆ’ r) (r โ‰  1) ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ = ์ดˆํ•ญ ร— (1 โˆ’ ๊ณต๋น„n)(1 โˆ’ ๊ณต๋น„) r = 1 ์ผ ๋•Œ ๋“ฑ๋น„์ˆ˜์—ด์˜ ์ˆ˜๋Š” ๋ชจ๋‘ ์ฒซ ํ•ญ๊ณผ ๋™์ผํ•˜๋ฏ€๋กœ ๋‹ค์Œ๊ณผ ๊ฐ™์Šต๋‹ˆ๋‹ค. Sn\= a + a + a + ... + a + a = na ๋”ฐ๋ผ์„œ Sn = na (r = 1) ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ = n ร— ์ดˆํ•ญ ### n๋ฒˆ์งธ์—์„œ m๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ n๋ฒˆ์งธ์—์„œ m๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ์„ ๊ณ„์‚ฐํ•˜๋Š” ๊ฒฝ์šฐ๋„ ๋งˆ์ฐฌ๊ฐ€์ง€๋กœ ์ˆ˜์—ด์„ ๋ฐ˜๋Œ€๋กœ ํ•˜์—ฌ ์–‘๋ณ€์„ ๋”ํ•ฉ๋‹ˆ๋‹ค. | | | | | | | | | | | | | | | |---|---|---|---|---|---|---|---|---|---|---|---|---|---| | | Smโˆ’n | \= | arnโˆ’1 | \+ | arn | \+ | arn+1 | \+ ... + | armโˆ’2 | \+ | armโˆ’1 | | | | โˆ’ | rSmโˆ’n | \= | | | arn | \+ | arn+1 | \+ ... + | armโˆ’2 | \+ | armโˆ’1 | \+ | arm | | | Smโˆ’n โˆ’ rSmโˆ’n | \= | arnโˆ’1 โˆ’ arm | | | | | | | | | | | ์ขŒ๋ณ€์€ rSm-n -Sm-n๊ฐ€ ๋˜๊ณ , ์šฐ๋ณ€์€ ๋„์ค‘์˜ ๋ถ€๋ถ„์ด ๋ชจ๋‘ ์‚ฌ๋ผ์ง€๋ฏ€๋กœ, arn-1 โˆ’ arm์ž…๋‹ˆ๋‹ค. rSmโˆ’n โˆ’ Smโˆ’n = arnโˆ’1 โˆ’ arm ์ด๊ฒƒ์„ Sm-n์— ๋Œ€ํ•ด ํ’€์–ด ๋ด…์‹œ๋‹ค. Smโˆ’n(1 โˆ’ r) = a(rnโˆ’1 โˆ’ rm) Smโˆ’n\= a(rnโˆ’1 โˆ’ rm)(1 โˆ’ r) ๋”ฐ๋ผ์„œ Smโˆ’n\= a(rnโˆ’1 โˆ’ rm)(1 โˆ’ r) (r โ‰  1) n๋ฒˆ์งธ์—์„œ m๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ = ์ดˆํ•ญ ร— (๊ณต๋น„nโˆ’1 โˆ’ ๊ณต๋น„m)(1 โˆ’ ๊ณต๋น„) r = 1 ์ผ ๋•Œ ๋“ฑ๋น„์ˆ˜์—ด์˜ ์ˆ˜๋Š” ๋ชจ๋‘ ์ฒซ ํ•ญ๊ณผ ๋™์ผํ•˜๋ฏ€๋กœ ๋‹ค์Œ๊ณผ ๊ฐ™์Šต๋‹ˆ๋‹ค. Smโˆ’n\= a + a + a + ... + a + a = (m โˆ’ n + 1)a ๋”ฐ๋ผ์„œ Smโˆ’n = (m โˆ’ n + 1)a (r = 1) ์ฒซํ•ญ๋ถ€ํ„ฐ n๋ฒˆ์งธ๊นŒ์ง€์˜ ํ•ฉ = (m โˆ’ n + 1) ร— ์ดˆํ•ญ
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Unparsed URLcom,calc-site!ko,/progressions/geometric_sum s443