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数学 高校生

なぜOG:GH=1:2なのですか?

考え方 練習 348 例題 348 オイラー線 △ABCの外接円の中心を0とし、頂点A,B,Cの点Oを基点とする 位置ベクトルを,それぞれ a, , こ とする. 位置ベクトル h =a+b+c で表される点をH, △ABCの重心をGとするとき,次の 問いに答えよ. $JCA (1) 3点 0, G, H は一直線上にあることを示せ . (2) 点Hは△ABC の垂心であることを示せ . SONS (1) 3点O,G,Hが一直線上にある OH =kOG の形で表せる (2)点Hは△ABCの垂心 Focus また、点は外接円の中心だから |==|| 3.685206(OA+OB+OC)-OGR FOR =3OG-OG=20G AHBC, BHICA つまり, AH・BC=0, BH・CA=0 つまりよって,3点0,G,Hは一直線上にある. (別解) GH = AH-AG=OB+OC- (OG-OA) の大温kg ADCƏ (1) OH=a+b+c, OG=1/(1+6+2) より, OH=3OGOH=kOG の形で 3 よって、3点0, G, Hは一直線上にある . ができる (2) 点Oは△ABCの外心だから, |a|=|8|=||| AH・BC=(OB+OC) ・(OC-OB) =(c+b). (c−b) >5508 よって, BH CA=(OA+OČ) (OA-OC)B ^¹ =(a+c)·(a−ĉ)¯AS 12-10 AH•BC=0\ 0803 H = 0 を利用 (内積) 5 3 ベクトルと図形 61 ** A O G 線分が垂直 注 三角形の外心O, 重心G,垂心Hは一直線上にあり, OG: GH = 1:2 である. (直線OGH をオイラー線という.) M C OG: GH=1:2 AH-OH-OA, OH = OA+OB+OC より 08055-3-57 (0) 0200315 20 AH=OB+OC OĞ=(a+b+c) =lap²-1c²²=005 (SCE BH・CA = 0 よって, 以上より, AH⊥BC, BHICA だから,点Hは△ABC A = 0, BH ±0 とし ても一般性を失わない. の垂心である. BH=OH-OB OH = OA+OB+OC より, BH = OA+OC rernzelni. の方面 例題 348 において, 点Cを通り外接円の直径となるようなもう一方の円周上 の点をEとするとき,四角形 AEBH は平行四辺形となることを示せ. →p. 63028

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英語 高校生

和訳お願いします。

次の英文を読んで, 設問に答えなさい。 [5] The headline grabs your attention: "The ancient tool used in Japan to boost memory." You've been The Japanese art of racking up clicks online more forgetful recently, and maybe this mysterious instrument from the other side of the world, no less! could help out? You click the link, and hit play on the video, awaiting this information that's bound to change your life. The answer? A soroban (abacus). Hmm, () それは私がどこに鍵を置いたか覚えておく助けになりそうには ないですよね? This BBC creation is part of a series called "Japan 2020," a set of Japan-centric content looking at various inoffensive topics, from the history of Hiroshima-style okonomiyaki pancakes to pearl divers. The abacus entry, along with a video titled "Japan's ancient philosophy that helps us accept our flaws," about kintsugi (a technique that involves repairing ceramics with gold-or silver-dusted lacquer), cross over into a popular style of exploring the country: Welcome to the Japan that can fix you. For the bulk of the internet's existence, Western online focus toward the nation has been of the "weird Japan" variety, which zeroes in rare happenings and micro "trends," but presents them as part of everyday life, usually just to entertain. This sometimes veers into "get a load of this country" posturing to get more views online. It's not exclusive to the web traditional media indulges, too but it proliferates online. Bagel heads, used underwear vending machines, rent-a-family services - it's a tired form of reporting that has been heavily criticized in recent times, though that doesn't stop articles and YouTube videos from diving into "weird Japan." These days, wacky topics have given way to celebrations of the seemingly boring. This started with the global popularity of Marie Kondo's KonMari Method of organizing in the early 2010s, which inspired books and TV shows. It's online where content attempts to fill a never-ending pit - where breakdowns of, advice and opinions about Kondo emerged the most. Then came other Japanese ways to change your life. CNBC contributor Sarah Harvey tried kakeibo, described in the headline as "the Japanese art of saving money." This "art" is actually just writing things down in a notebook. Ikigai is a popular go-to, with articles and videos popping up all the time explaining the mysterious concept of ... having a purpose in life. This isn't a totally new development in history, as Japanese concepts such as wa and wabi sabi have long earned attention from places like the United States, sometimes from a place of pure curiosity and sometimes as pre-internet "life hacks" aimed making one's existence a little better. (B) The web just made these inescapable. There's certainly an element of exoticization in Western writers treating hum-drum activities secrets from Asia. There are also plenty of Japanese people helping to spread these ideas, albeit mostly in the form of books like Ken Mogi's "The Little Book of Ikigai." It can result in dissonance. Naoko Takei Moore promotes the use of donabe, a type of cooking pot, and was interviewed by The New York Times for a small feature this past March about the tool. Non- Japanese Twitter users, in a sign of growing negative reactions to the "X, the Japanese art of Y" presentations, attacked the piece... or at least the headline, as it seemed few dove the actual content of the article (shocking!), which is a quick and pleasant profile of Takei Moore, a woman celebrating her country's culinary culture. Still, despite the criticism by online readers, the piece says way more about what English-language readers want in their own lives than anything about modern Japan. That's common in all of this content, and points to a greater desire for change, whether via a new cooking tool or a "Japanese technique to overcome laziness." The Japan part is just flashy branding, going to a country that 84% of Americans view positively find attention-grabbing ideas for a never-ending stream of online content. And what do readers want? Self-help. Wherever they can get it. Telling them to slow down and look inside isn't nearly as catchy as offering them magical solutions from ancient Japan.

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英語 高校生

4の解き方がわかりません。 例えば(a)で、続く文であくびを謝っていることも全て把握した上で、挨拶なのでpolitelyかと考えたのですが、なぜ誤りなのか教えていただきたいです。

13 Lucy is a British schoolgirl who lives in Oxford. She is talking to her father, Fred, in the kitchen of their home. Read the conversation below and answer the following questions. Lucy: (a) Good morning, Dad. Oh, sorry for yawning. What are you doing with that microwave oven? It looks heavy. Do you need a hand with moving it? Fred: I think I'll be OK, Lucy. I'm just going to put it in the car and take it to the city dump. Lucy: Couldn't you send it away to be repaired? Fred: It's ten years old and well out of warranty now, so I very much doubt that the manufacturer would do it. They probably don't even carry the spare parts anymore. Lucy: That's a shame. Oh, I know what! Why not take it to the Repair Café near my school? Fred: What's that? I've never heard of it. Lucy: It's brilliant! We visited it as part of our environmental science course recently. It's a meeting place where people can get together to mend broken items cooperatively. And have a chat and a cup of coffee! Fred: I'm all ears. Tell me more. Lucy: Well, the first Repair Café was started by a Dutch woman called Martine Postma in Amsterdam in 2009. (1) 彼女は,使い捨て文化で環境が破壊されて, ゴミの量が地球規模で増えることを心配してたん . She wanted to find a local solution to this global problem. Fred: That's what they call "thinking globally, acting locally," isn't it? Lucy: Exactly. She also wanted to address the decline in community spirit amongst urban dwellers and do something about people's loss of practical skills and ingenuity. Fred: And the idea (2) caught on? Lucy: Very much so. The concept has grown into a global movement. The one in Oxford started about four years ago. Fred: Impressive! What kind of things do they repair? Lucy: Oh, all sorts. Electrical appliances, clothes, furniture, crockery, bicycles, and even toys. Fred: How successful are they at repairing things? Lucy: Well, of course, they cannot guarantee to fix every item brought to them, but they have a fairly good success rate. One study found that on average 60 to 70 percent of items were repaired. The rate is higher for some items such as bicycles and clothes but lower for things like laptop computers. Fred: I can understand that. Just between you and me, I think some electronics manufacturers deliberately make products in such a way that you cannot disassemble them and repair them unless you have specialized tools and equipment. Lucy: Yes, and that's where Repair Cafés can help. But these cafés are not just about repairing things for people. They are places where we can meet others, share ideas, and be inspired. The volunteer repairers are very keen to involve the visitors in thinking about the repair and actually carrying out the repair themselves. They also encourage people to think about living together in more sustainable communities. Fred: I suppose you could say they are about repairing our minds, not just our things. Lucy: Quite so, although often the two are very closely related. Many people attach (3)sentimental value to old things that might, for example, be part of their family history. Fred: I see what you mean. It almost sounds too good to be true. (a)Is there a catch? For example, how much does it cost? Lucy: Advice and help from the repairers is free, but people who use the café are invited to make a donation. That money is used to cover the costs involved in running the café. If specific spare parts are needed, the repairers will advise you on how to obtain them. Fred: Well, that's marvelous! (e)Then I'll take this old microwave there. Are they open today? Lucy: Yes, and I'll come with you. I've got a pair of jeans that are badly in need of some attention. QUESTIONS 1. Translate the underlined part after (1) into English. 2. What does the underlined phrase after (2) mean? Select the most appropriate expression from the list below. (A) became popular (B) hit a dead end (C) occurred to you (D) played a significant role (E) worked in practice 3. The underlined phrase after (3) means the value of an object which is derived from personal or emotional association rather than its material worth. Give ONE object that has "sentimental value" for you and explain why it has such value. Your answer should be between 15 and 20 English words in length. (Indicate the number of words you have written at the end of your answer.)

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英語 高校生

この問題、自分で読んでも全く内容が分からなかったのですがわかる方いらっしゃいますか?? ターゲット1900の単語だけだと足りませんか? また、文法はどのくらいのレベルでしょうか。参考書で教えていただけると助かります。 よければ問題の解説もお願いしたいです。 時間がある方どう... 続きを読む

Ⅰ. 次の英文を読んで、下の間に答えよ。 Early in the pandemic, Julie Van Rosendaal started to notice something (1) about the butter she was using in her cooking and baking. It seemed harder than it used to be. Van Rosendaal has a food blog (2) DinnerWith.Julie.com. She talks about food on CBC radio and writes about it in magazines and newspapers. Before, when she left butter out of the fridge, it used to go soft; it was easy to spread on bread. (3) these days, she noticed that if she wanted soft butter, she had to put it in the microwave. If she used it right out of the cupboard, it would tear holes in her bread. Was her kitchen too chilly? Or had something about Canadian butter changed? On Feb. 5, Van Rosendaal posted her suspicions on social media. More than a thousand people on Facebook and hundreds on Twitter commented that they had been noticing the ( 4 ) thing. The answer seems to be that Canadian dairy cows, which produce the milk that is made into Canadian butter, (5) likely being fed more palm oil fats in their feed than before, XV As more people began doing more baking and bread making during the pandemic, the demand for butter went up. Using palm fats in livestock feed can increase the amount of milk cows produce, which helps farmers to meet the increased demand for ( 6 ). Some people don't want palm fats in their diet, because they say it isn't heart-healthy. (7) say it changes the taste and texture of

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