A PHP Error was encountered

Severity: Warning

Message: mkdir(): Permission denied

Filename: libraries/Common.php

Line Number: 202

Backtrace:

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 202
Function: mkdir

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 236
Function: getLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 585
Function: parseLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 425
Function: initBoardView

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: file_put_contents(/DATA/upload/polymath/latex/8f4800a9771c6c31ace74376abf51f7a.gif): failed to open stream: No such file or directory

Filename: libraries/Common.php

Line Number: 213

Backtrace:

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 213
Function: file_put_contents

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 236
Function: getLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 585
Function: parseLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 425
Function: initBoardView

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: mkdir(): Permission denied

Filename: libraries/Common.php

Line Number: 202

Backtrace:

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 202
Function: mkdir

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 236
Function: getLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 585
Function: parseLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 425
Function: initBoardView

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: file_put_contents(/DATA/upload/polymath/latex/65b52e73799c10590c0daa7a0706d797.gif): failed to open stream: No such file or directory

Filename: libraries/Common.php

Line Number: 213

Backtrace:

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 213
Function: file_put_contents

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 236
Function: getLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 585
Function: parseLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 425
Function: initBoardView

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
Line: 315
Function: require_once

수학동아 - 폴리매스
본문바로가기
함께 풀고 싶은 문제
나도 수학쌤 문장제 문제를 변형해 문제를 내는 곳입니다.
[문장제 문제&개념응용] 오랜만에 단순문제라 지적받을 만한 것
피카파이 2021.08.11 22:00 조회 394

1. 모든 반비례 그래프는 닮음임을 보여라.

2. a-b= (√a)^2-(√b)^2라는 것을 사용해서 \sum_{k=1}^{x}(\sqrt{k+1}+\sqrt{k})   imes(\sqrt{k+1}-\sqrt{k})즉, ((\sqrt{2}+\sqrt{1})   imes(\sqrt{2}-\sqrt{1}))\: +\: ((\sqrt{3}+\sqrt{2})   imes(\sqrt{3}-\sqrt{2}))\: +\: ((\sqrt{4}+\sqrt{3})   imes(\sqrt{4}-\sqrt{3}))\: +\: ((\sqrt{5}+\sqrt{4})   imes(\sqrt{5}-\sqrt{4}))\: +\: ((\sqrt{6}+\sqrt{5})   imes(\sqrt{6}-\sqrt{5}))\: +\: ((\sqrt{7}+\sqrt{6})   imes(\sqrt{7}-\sqrt{6}))\: +\: ((\sqrt{8}+\sqrt{7})   imes(\sqrt{8}-\sqrt{7}))\: +\: ...\: +\: ((\sqrt{x+1}+\sqrt{x})   imes(\sqrt{x+1}-\sqrt{x}))를 구하여라.

(참고: 어려워 보이지만 쉽습니다.)

이 문제 어떠셨나요?

글쎄요

3

어려워요

0

  •  
    짱수학천재 Lv.7 2021.08.12 02:22

    ((\sqrt{2}+\sqrt{1})   imes(\sqrt{2}-\sqrt{1}))\: +\: ((\sqrt{3}+\sqrt{2})   imes(\sqrt{3}-\sqrt{2}))\: +\: ((\sqrt{4}+\sqrt{3})   imes(\sqrt{4}-\sqrt{3}))\: +\: ((\sqrt{5}+\sqrt{4})   imes(\sqrt{5}-\sqrt{4}))\: +\: ((\sqrt{6}+\sqrt{5})   imes(\sqrt{6}-\sqrt{5}))\: +\: ((\sqrt{7}+\sqrt{6})   imes(\sqrt{7}-\sqrt{6}))\: +\: ((\sqrt{8}+\sqrt{7})   imes(\sqrt{8}-\sqrt{7}))\: +\: ...\: +\: ((\sqrt{x+1}+\sqrt{x})   imes(\sqrt{x+1}-\sqrt{x}))를 구하여라.

    뭘까요????(시그마를 모르는 분들을 위하여)

    댓글 작성하기 좋아요0 댓글수2
    •  
      Amath Lv.8 2021.08.12 03:30

      닉네임이 독특하시네요..

      좋아요0
    •  
      피카파이 Lv.8 2021.08.12 04:13

      허걱 글자가 깨져 나왔네요...

      좋아요0
  •  
    민초싫은comar Lv.6 2021.08.13 00:55 비밀댓글
    비밀 댓글이 등록 되었습니다.
    댓글 작성하기 댓글수1
    •  
      피카파이 Lv.8 2021.08.13 18:11

      (이름만 단문이죠. 사람들이 단문이라고 이름을 하면 더 만힝 ㅡㄹㅋㅋ릭 하던데요?)

      좋아요0
  •  
    부분해결
    JM Lv.6 2021.08.18 23:45 비밀댓글
    비밀 댓글이 등록 되었습니다.
    댓글 작성하기 댓글수1
    •  
      피카파이 Lv.8 2021.08.19 05:47 비밀댓글
      비밀 댓글이 등록 되었습니다!
  •  
    부분해결
    JM Lv.6 2021.08.19 06:30 비밀댓글
    비밀 댓글이 등록 되었습니다.
    댓글 작성하기 댓글수0
  •  
    해결
    JM Lv.6 2021.08.19 06:36 비밀댓글
    비밀 댓글이 등록 되었습니다.
    댓글 작성하기 댓글수1
    •  
      피카파이 Lv.8 2021.08.19 22:17

      허걱 반직선이 아니라 반비례 그래프네요;;ㄷㄷ

      좋아요0
  • 폴리매스 문제는 과학기술진흥기금 및 복권기금의 재원으로 운영되고, 과학기술정보통신부와 한국과학창의재단의 지원을 받아 수행된 성과물로 우리나라의 과학기술 발전과 사회적 가치 증진에 기여하고 있습니다.

  • ☎문의 02-6749-3911