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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

2枚目の画像の赤線部分の 「A man that had his life enter the twists and turns that occur in all our lives, but in his case, the road stopped much too ... 続きを読む

次の英文を読んで, a~ f の 2 ]内の語(句) を正しく並べ替え, 本文中の 【 (1) 】 ~ 【(6) 】の適切な場所に入れなさい。 (a,bなどの記号は書かず,並べ替えた英文を記入するこ と) My first real job. Thirteen years since high school in training, in hospitals, in books. All of a sudden at 8 a.m. tomorrow morning I would suddenly become Dr. Dhillon. Time to heal and fix. I began my first real posting as a rural physician in a small town in rural Saskatchewan. A beautiful little hospital, staff happy to see a young doctor in town, and the welcoming red and green of the local Co-op sign. The day began innocuously enough: morning rounds at the hospital, learning about all the patients who had been handed over to my care for the next two weeks; trying to decipher other physicians' illegible writing and promising to never let mine get that bad, and failing quickly at that. C "Hello, good morning. My name is Dr. Dhillon and 【 (1) little while until your doctor is back." With a vague idea of what was actually happening inside each patient's body, and not a clue what was happening in their minds, I popped in from room to room as 【 (2) 】 of things to check and recheck after the morning ward round was done.//Thankfully, the nurses were there to handle any miscues and give me a vital, two-to-three-sentence summary of the patient and any concerns before entering into their realm with a quick knock on a half-opened door. When I got to the last patient I was to see that morning, I found his door was closed. It was at the back corner of the hospital. It was darker. "This is Gary, he's dying." The nurse's tone of voice lowered, naturally, to the level we use when discussing death, just in case death was nearby and would hear and come hither to hasten the process. "Metastatic, it was too late when he came in. Really sad story. He's still so young." She continued. I gently knocked, lighter, more gently 【 (3) 】 a gall-bladder attack whom I had just chatted to. "Hello Gary, how are you this morning?" is what I said. "Hello, who are you?" he asked. "My name is Paul and I'll be your doctor until your normal doctor comes back." I couldn't bear to say I was Dr. Dhillon. What was I going to doctor in his case? "I'm leaving on Tuesday. Next week. To be closer to home," he said. "That's great, so that's something to look forward to then." Inside, I wondered, Was that

解決済み 回答数: 3