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Mathematics Senior High

赤線で引いたところの意味が分かりません

428 000 分の垂直に関する証明 △ABCの重心を G. 外接円の中心を0とするとき、次のことを示せ。 (1) OA+OB+OCOH である点H をとると, Hは△ABCの垂心である。 GH-20G 七 基本例題 30 基本23 基本 指針 (1) 三角形の重心とは、三角形の各頂点から対辺またはその延長に下ろした垂線の交点で AH ¥1, BC +1. BF 0, CÃ +1のとき AHLBC, BHLCA であるから、内積を利用して、 ○は△ABCの外心であるから, OA|=|OB|-|OC | も利用。 (2) (1) の点に対して, 3点O, G, Hは一直線上にあり [類 山梨大] 【CHART 線分の垂直 (内積) = 0 を利用 解答 (1) A=90° /B=90° としてよい。 このとき, 外心Oは辺BC, CA上 にはない。 ① OH = OA + OB+OC から ****** AH-OH-OA=OB+OC ゆえに AH-BC - (OB+OC)-(OC-OB) = |OC|-|OB|³=0 同様にして ・・・・・・ ④ AH-BC-0, BH-CA=0 人 [(内積) = 0) を計算により示す。 B BH.CA=(OA+OC).(OA-OĆ) -|OA|-|OC|²=0 また①から AH=OB+OC+0, BH=OA+OC+0 よって, AH = 0, BC=0, BH ¥0, CA ¥0 であるから AHBC, BHICA すなわち AH⊥BC, BHICA したがって, 点Hは△ABCの垂心である。 OA (2) OC=ON+O3+OC_110F から OH-3OG 3 ゆえに CH-OH-OG=2OG よって, 3点O, G, Hは一直線上にあり 練習 右の図のように, △ABCの外側に GH=2OG n 直角三角形のときは ∠C=90° とする。 このとき,外心は辺AB上 にある (辺ABの中点) BC=OC-OB (分割) △ABCの外心0→ OA = OBOC (数学A) (検討) 外心, 重心,垂心を通る直 (この例題の直線OGH) を オイラー線という。 ただし、正三角形は除く。 <(1) から OA+OR+OCOH 鋭食 (1) (2) (1) C [①]

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English Senior High

間違いありますか?教えてほしいです

A ( )に入る最も適当なものを選びなさい。 101. I was tired ( ) listening to her complaints. 4 of beyond 2 to 3 at 102. The plane couldn't take ( ) owing to the storm. 1 on 103. A fire ( off 3 in 4 up ) out in my neighborhood last night. 2 happened 3 occurred (4) rose broke 104. She finally picked ( ) an evening dress for the party. 0 at @off (3) on out 105. Naomi lived in Bangkok for a year, so she should be familiar ( customs. ) me. on "" assure 2 bet 3 count on 4 depend 1 of 2 in 3 with 4 on 106. I went ( ) a department store last Sunday. shopping at 2 shopping to 3 to shopping at 4 to shopping to 107. “Will you come with me when I go speak to the boss?" "Of course. You can ( (慶応大) 108. Columbia was named ( in 0 after 2 at 109. My uncle ( 0 dropped in at 110. People finding fault ( Oby 2 of 3 on with 111. My friend suddenly got ill, so I ( ) Christopher Columbus. 4 on 2 off ) my apartment yesterday. 2 dropped in on 3 stopped over in looked on 2 brought up 3 sent for ) to do such a thing. 112. She knows ( too clever clever enough 3 better than 113. You are getting too old for football, Mr. Brown. instead. ) others often do not see their own. ) a doctor. over 4 up (大阪商業大) set out (湖北短大) (千葉工業大 ) (湖北短大) ) Thai (名古屋学院大) (中部大) (中部大) (日本大) 4 dropped in with (京都産業大) (武庫川女子大) (四天王寺国際仏教大) 4 more than You had better take ( ) golf (共立女子大)

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Mathematics Senior High

〇〇のとき と、範囲を決めるとき、中央の値を求める場合と、問題文の範囲をそのまま使う時があるんですけど、違いってなんですか?

(1) 定義域 0≦x≦2の中央の値は1で ある。 [1] a <1のとき 図 [1] から,x=2で最大となる。 最大値は f(2)=22-2a2+a=4-3a [2] α=1のとき 図 [2] から, x=0, 2 で最大となる。 最大値は f(0)=f(2)=1 [3] 1 <a のとき 図[3] から, x=0で最大となる。 最大値は f(0)=a 484 [1]~[3] から a <1 のとき α=1のとき α>1 のとき x=0 で最大値 α (2) [4] a < 0 のとき SUNS 図 [4] から, x=0 で最小となる。 最小値は f(0)=a [5] 0≦a≦2のとき 図 [5] から, x=αで最小となる。 最小値は f(a)=-a²+a [4]~[6] から a<0 のとき x=2で最大値4-3a x=0, 2 で最大値1 110 [6] 2 <a のとき 図 [6] から, x=2で最小となる。 最小値は f (2) =4-3a [1]\ PRACTICE 643 ABC [2]\ [3] x=0x=ax=2 最 最大 Xx=0x=ax=2 大 [6] [4] 軸| x=0x=1x=2 1x=1| x=0 で最小値 α 0≦a≦2のとき x =α で最小値- α²+α a>2のとき x=2で最小値 4-3a [5] 軸 30 最 大 como e 掛軸 最小 x = 0 x=ax=0 x=2 最大 大 最小 x=0x=ax=2 最小 |軸 [1] 軸が定義域の中央 x=1 より左にあるから, x=2 の方が軸より遠い。 よって f(0)<f(2) x=2x=a [2] 軸が定義域の中央 x=1 に一致するから, 軸と x=0, 2 の距離が等しい。 よって f(0)=f(2) [3] 軸が定義域の中央 x=1 より右にあるから,x=0 の方が軸より遠い。 よって f(0) f(2) 答えを最後にまとめて 書く。 S [4]軸が定義域の左外にあ るから, 定義域の左端で 最小となる。 $+55 [s] [5]軸が定義域内にあるか I= ら、頂点で最小となる。 #37 [ɛ] 0-2 2007 [6] 軸が定義域の右外にあ るから、定義域の右端で 最小となる。 VSE TIVE 答えを最後にまとめて 書く。 <D 115 3章 8 2次関数の最大・最小と決定

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English Senior High

全文訳お願いします!

4 20 科学 420 words Chapter 1 The recipe for making any creature is written in its DNA. So last year, when 1-1 geneticists* published the near-complete DNA sequence of the long-extinct woolly mammoth, there was much speculation about whether we could bring this giant creature back to life. 5 東京理科大学 Creating a living, breathing creature from a genome* sequence that exists only in a computer's memory is not possible right now. But someone someday is sure to try it, predicts Stephan Schuster, a molecular biologist at Pennsylvania State University and a driving force behind the mammoth genome project. So besides the mammoth, what other extinct beasts might we bring back to life? Well, 12 10 it is only going to be possible with creatures for which we can recover a complete genome Without one, there is no chance. And usually when a creature dies, the (1) - DNA in any flesh left untouched is soon destroyed as it is attacked by sunshine and bacteria. sequence. There are, however, some circumstances in which DNA can be preserved. If your 15 specimen froze to death in an icy wasteland such as Siberia, or died in a dark cave or a really dry region, for instance, then the probability of finding some intact stretches of DNA is much higher. Even in ideal conditions, though, no genetic information is likely to survive more than a million years. - so dinosaurs are out and only much younger remains are likely to yield good-quality DNA. "It's really only worth studying specimens that are less than 100,000 years old," says Schuster. The genomes of several extinct species besides the mammoth are already being sequenced, but turning these into living creatures will not be easy. "It's hard to say that something will never ever be possible," says Svante Pääbo of the Max Planck Institute 25 for Evolutionary Anthropology in Germany, "but it would require technologies so far removed from what we currently have that I cannot imagine how it would be done." But then (3) 50 years ago, who would have believed we would now be able to read the instructions for making humans, fix inherited diseases, clone mammals and be close to creating artificial life? Assuming that we will develop the necessary technology, we have 30 selected ten extinct creatures that might one day be resurrected. Our choice is based not just on practicality, but also on each animal's "charisma" - just how exciting the prospect of resurrecting these animals is. 1-3

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