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数学 高校生

青チャートのAです かっこ1で証明に使わない角についてわざわz言及しているのはなぜですか

87 基本例題 接弦定理の逆の利用 00000 10の外部に接線 PA, PB を引く。 点Bを通り, PAと平行 SCOUT な直線が円0と再び交わる点をCとする。 <PAB=a とするとき, ∠BACをaを用いて表せ。 直線 AC は △PAB の外接円の接線であることを証明せよ。 指針 (1) 円の外部の1点からその円に引いた2本の接線の長さは等しいことや, 接弦定理, 平行線の同位角・錯角に注目して,∠PAB に等しい角をいくつか見つける。 (2) 接線であることの証明に、次の接弦定理の逆を利用する。 0,348 TERA 円 0 の弧 AB と半直線 AT が直線 AB に関して同じ側にあって ∠ACB=∠BAT ならば,直線ATは点Aで円0に接する (1) の結果を利用して,∠APB=∠BAC を示す。 解答 (1) PA=PBであるから ∠PAB=∠PBA=a また, PA//BC であるから ∠ABC=∠PAB=α 更に ∠ACB=∠PAB=α よって, △ABCにおいて ∠BAC=180°−2a ...... P おいて、円の CHART》 接線であることの証明 接弦定理の逆が有効 (19) A B89 使わない DETERA ∠APB=180°-2a 0円 13 p.436 基本事項 ② ...... A HA3 | 接線の長さの相等。 a NGAPDATA C onit SA SEN 09:A ART SI (2) AAPBにおいて 1⑩② から ∠APB=∠BAC THIAPATIA したがって,直線 AC は △PAB の外接円の接線である。 A4 接弦定理の逆 B 439 T > 平行線の錯角は等しい 接弦定理 PROL PA- とし、その手をとすると、名は てみよし、これから △PAB は二等辺三角形。 79-84-A4 A 章 144 円と直線、2つの円の位置関係 <DO & FR>

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英語 高校生

英語長文の定期試験の問題なのですが、最初のAの正誤問題のcがT(正)になる理由が分かりません。 問題文のcの文章には Nasa succeeded in cutting down on the sound とあり、 本文には画像の蛍光ペンを引いた箇所の通り Nasa h... 続きを読む

英語長文演習1学期中間試験 問題用紙 ※解答はすべて、 解答用紙に記入しなさい。 ※解答用紙のみ切り離して提出する。 1 Read the following essay and answer the questions. Most commercial airplanes travel at about 500 to 600 miles per hour. SR-71 Blackbird, which was developed by Lockheed Martin in the 1960s, could fly as fast as 2500 miles per hour. At that speed, you could go from Tokyo to New York in just around three hours. So why does it still take so long for ordinary people to fly? I The to shatter windows One of the biggest problems is that when a plane flies faster than the speed of sound it breaks the sound barrier, causing a sonic boom. This boom is thousands of feet below the plane. II Unfortunately, a lack of fuel efficiency and the high costs of maintenance made it unprofitable. It retired in 2003, just a few years after a major accident. But the dream of supersonic travel never died, and engineers at NASA have finally figured out a way to reduce the sound of a sonic boom to little more than that of a car door shutting. III If all goes well, they will use the data they collect to try to convince regulators to update aviation laws to allow commercial supersonic flight. At least three companies in the US are hoping to advantage of such a change, and they aim to put supersonic planes in the air within the next decade. QUESTIONS: A About the following explanations, put T if it is true, and put F if it is false. Qa. Before realizing the dream of supersonic travel, aviation laws must be changed. b. In 1960s, ordinary people could go from Tokyo to New York in just around three hours. c. Nasa succeeded in cutting down on the sound made by supersonic airplanes. d. The Concorde flew much faster than ordinary commercial airplanes. e. Supersonic airplanes can do damage to houses or buildings when they fly over land. BChoose the right sentence to fill in III a. NASA is hoping to run test flights over land in 2022. b. Military airplanes fly at speeds many times that. c. That's why the Concorde, a supersonic plane that traveled at around 1500 miles per hour, was mostly limited to routes above the ocean. CChoose the appropriate word or phrase to fill in ★ and ☆ . ★ b. so loud c. loud enough a. too loud d. louder a. make b. take C. gain d. share

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数学 高校生

78の(2)の問題なんですけど答えが32分の7になるんですけどなぜそうなるのかが分かりません。教えてください

75.4本の当たりくじを含む 10本のくじがある。 A, B, Cの 3人がこの順に くじを1本ずつ引く。 ただし, 引いたくじはもとに戻すものとする。こ のとき, AとCが当たり, Bがはずれる確率を求めよ。 76.2つの袋A, Bがあり, Aには赤球3個と白球7個, Bには赤球2個と白球 3個が入っている。A, Bの袋から球を2個すずつ取り出すとき, 4個の球 がすべて同じ色になる確率を求めよ。 77. ある商品を買ったときにはーの確率で景品が入っている。 この商品を 4個買ったとき, 次の場合の確率を求めよ。 (1) ちょうど3個の景品が手に入る (2) 少なくとも1個の景品が手に入る 78. 点Pは, 数直線上の原点Oから出発し, さいころの出る目が奇数ならば +1だけ,偶数ならば -1だけ移動する。 さいころを8回投げて, Pがち ょうど次の点にくる確率を求めよ。 (1) 原点0 (2) 点A P -8 -6 -4 2 A 0 2 4 6 79.1から 20 までの数を1つずつ書いた 20枚の札から1枚引くとき 2の倍数が書かれた札を引く事象をA 3の倍数が書かれた札を引く事象をB とする。このとき,条件付き確率 PA(B), PdA)を求めよ。 80.1から5までの数を1つずつ書いた5枚の札から1枚引いて, その札を 6から 10 までの数を1つずつ書いた5枚の札とー緒にする。次に,この 6枚の札から1枚の札を引くことにする。 このとき, 最後に引く札が偶 数が書かれた札である確率を求めよ。 1)3

未解決 回答数: 1
英語 高校生

アから順番に12131であってますか? わかる方教えてください!! お願いします!

Earth has two sets of poles: the geographic poles and the magnetic poles. The geographic poles are located at the northemmost and southernmost ends of the earth. The location of the magnetic poles, on the other hand, are ( ア ) moving, This fact has several implications for navigation and transportation. Shifts in the position of the North Magnetic Pole are nothing new. Since 1831, scientists have been tracking its location. The movements are caused by changes in the flow of swirling molten iron in the earth's core which affect how the earth's magnetic field behaves. What is surprising to scientists is the speed at which the pole has been moving in recent years. For most of the 20th century, magnetic north was located around the northern parts of Canada. It drifted around, moving slowly north at an ( イ ) speed of approximately 10 kilometers per year. In recent decades, that rate has increased significantly to about 55 kilometers per year. The North Magnetic Pole is now moving away from Canada toward eastem Russia. While scientists can't fully explain how changes in the carth's molten core are affecting the pole's movement, they can map the earth's magnetic field. Doing so allows them to ( ウ) hé rate of change over time. This, in turn, provides information on how the magnetic field may shift in the future. Information on changes to the earth's magnetic field is used to produce the World Magnetic Model (WMM). This model is used as the basis for all fornms of modern navigation, from how ships move at sea to mapping software in smartphones. ( エ) in the model, caused by shifts in the real location of the North Magnetic Pole, can seriously impact almost all foms of modern transportation. The model is updated every five years, but in 2018, during routine checks of the 2015- 2020 model cycle, scientists noticed a problem. Because of the rapidly shifting pole, the WMM was close to being outside the acceptable limits for navigational errors. This forced the release of an updated version of the model、 It was revised ( オ ) in 2020, and the current version is expected to last until 2024, As well as keeping track of the WMM's accuracy, scientists continue investigating why the magnetic field is changing so dramatically. This essential work will ensure a safe journey for everyone navigating their way through the world.

未解決 回答数: 1
英語 高校生

ア順番に12131であってますか? わかる方教えてください!!!! お願いします!

For most of the 20th century, magnetic north was located around the northern parts of molten iron in the earth's core which affect how the earth's magnetic field behaves. What is surprising to scientists is the speed at which the pole has been moving in recent years. magnetic poles, on the other hand, are ( ア ) moving. This fact has several implications poles are located at the northernmost and southernmost ends of the earth. The location of the Shifts in the position of the North Magnetic Pole are nothing new. Since 1831, scientists Earth has two sets of poles: the geographic poles and the magnetic poles. The geographic have been tracking its location. The movements are caused by changes in the flow of swirling for navigation and transportation. Canada. It drified around, moving slowiy north at an ( イ ) speed of approximately 10 MIometers per year. In recent decades. that rate has increased significantly to about 3 KIIometers per year. The North Magnetic Pole is nowmoving away from Canada toward eastern Russia. While scientists can't fully explain how changes in the earth's molten core are affecting the pole's movement, they can map the earth's magnetic field. Doing so allows them to (ウ ) the rate of change over time. This, in turn, provides information on how the magnetic field may shift in the future. Information on changes to the earth's magnetic field is used to produce the World Magnetic Model (WMM). This model is used as the basis for all forms of modern navigation, from how ships move at sea to mapping software in smartphones. ( エ ) inthe model, caused by shits in the real location of the North Magnetic Pole, can seriously impact almost all forms of moderntransportation. The model is updated every five years, but in 2018, during routine checks of the 2015- 2020 model cycle, scientists noticed a problem. Because of the rapidly shifting pole, the WMM was close to being outside the acceptable limits for navigational errors. This forced the release of an updated version of the model. was revised ( オ ) in2020, and the current version is expected to last until 2024. As well as keeping track of the WMM's accuracy, scientists continue investigating why the magnetic ficld is changing so dramatically. This essential work will ensure a safe journey for everyone navigating their way through the world.

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