수학동아 - 폴리매스

함께 풀고 싶은 문제

나도 수학쌤 문장제 문제를 변형해 문제를 내는 곳입니다.

[문장제 문제&개념응용] 제곱의 합1단계

피카파이 2021.03.14 19:12 조회 493

문제 푼 사람 0명

페이스북 트위터 카카오톡 카카오스토리 네이버블로그 네이버밴드

( $k=1\sum k^{2}$ n까지 더하기)즉 1 $1^{2} +2^{2} +3^{2}+...n^{2}$ =왜( ( $(1*(n-0))+(2*(n-1))+(3*(n-2))$ ......(언젠가는 끝남)*2) $-(1+2+3+4+...n)$

이전글 다시 집으로-몰랑과 수파 최종화

다음글 7-segment display

이 문제 어떠셨나요?

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222 Lv.9 2021.03.14 20:22

문제 이해가 어려우신 분들을 위해: 1^2+2^2+3^2+.... = =왜( $(1*(n-0))+(2*(n-1))+(3*(n-2))$ +... $-(1+2+3+4+...n)$

인지를 증명하시오. 이런 문제입니다.

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- 피카파이 Lv.8 2022.07.25 00:57
  
  222님이 활동하던 시절
  
  좋아요0
바람개비 Lv.5 2021.03.14 20:47

n=1인 경우부터 이미 잘못되었어요.

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- 피카파이 Lv.8 2021.03.14 21:18
  
  앗!문제 수정합니다.
  
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- 피카파이 Lv.8 2021.03.14 21:22
  
  *2를 빼먹었습니다.
  
  좋아요0
바람개비 Lv.5 2021.03.15 00:51 비밀댓글

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비밀 댓글이 등록 되었습니다.

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- 피카파이 Lv.8 2021.03.15 16:20
  
  에~
  
  좋아요0
- 피카파이 Lv.8 2021.03.15 16:22 비밀댓글
  
  비밀 댓글이 등록 되었습니다!
- 바람개비 Lv.5 2021.03.15 18:54
  
  수식입력기에서 시그마 기호에 커서 올리면 바로 아래에 있습니다.
  
  좋아요0
- PF＿ Lv.8 2021.03.16 01:37
  
  @바람개비
  
  첫 댓글의 작성자가 본인인 경우에는 그 댓글에 비댓을 달면 출제자도 못 봐요...
  
  (그냥 따로 비댓으로 달아주시는게 최선입니다)
  
  좋아요1
피카파이 Lv.8 2022.07.25 00:55

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