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数学 中学生

2023年東京学芸大学附属高等学校、数学の問題です。 解説を見てもいまいちよくわかりません。解説お願いします!

3 右の図のように, 点 O(0, 0), 点A (2,0), 点B (1, 0) がある。 また、直線と直線 mがあり、 直線の 式は x = 2, 直線 m YA 1 1 10 B(1,0) A x (2,0) m の式はx=1である。 点から点 (10) ま での距離, および点から点(0, 1) までの距離をそれぞ れ 1cm とする。 点Pは点Oを出発し、軸上を座標が増加する方向 に毎秒1cm の速さで動く。点Qは点Pが出発するの と同時に点Aを出発し、直線上を y 座標が増加する方 向に毎秒1cm の速さで動く。 点Rは, 点Pが出発して 3 秒後に点Bを出発し、 直線上をy 座標が増 から 10 加する方向に毎秒1cm の速さで動く。 点Pが点Oを出発してから t秒後について,次の各問 〔3〕P を通り,直線 QR に平行な直線を引き,直線m と いに答えなさい。 ただし, 3 10 交わる点をPとすると, PP' // RQ より, <t <1とする。 △PQR =△P'QR となる。 直線 PP' の式は、 〔1〕 t =1/12 のときの直線QRの傾きを求めなさい。 (6点) 〔2〕3点P,Q,Rが1つの直線上にあるときの t の値 を求めなさい。 (6点) [3] APQR の面積が べて求めなさい。 cm²になるときの t の値をす (8点) 左が問題。下が解説です。 y=3/10(x-t)が意味わかりません y = 3 (z-t) であるから,P'のy座標は (1-t) 10 3 10 の面積を P'R を底辺と考えると高さが1cm/にな AP'QR 1 10 2 cm² となるのは, 1/2P'R=1/10 3 (1 – t) - ( t - ₁0 ) = + 1/3 10 8 4 13'13 るので,この面積が 3 10 t= のときである。 13t-6= ±2

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英語 中学生

緑の線を引いているところの意味がわかりません。 その前のTwo girls were swimming in the lake.とその後のOne was the ...からは分かるのですがこの部分だけ日訳わ簡単なものの文脈が理解できません。この話自体ニュージーランド民話ら... 続きを読む

1 ウエヌクが出会った少女 [大阪教育大附高平野 制限時間 1回目: 20分 / 2回目(英文のみ) : 7分 This is the story of "Ue-nuku. Early one morning, before the sun was up, Ue-nuku was walking in the forest. He came to a lake. Two girls were swimming in the lake. They were girls of the sky. They were on earth for a little while. One _)( ) was the Rain-girl. 5 was the "Mist-girl, and ( Ue-nuku did not know who they were, but he knew that they were beautiful. They were so beautiful that 2[ he / how / know / marry / to /to/ wanted] one of them. But while he was watching, the sun came up. When the girls saw it was day, they were frightened. "We must 10 go!" they cried. "We are girls of the mist and rain. If the sun shines on us, we will die." While Ue-nuku watched, the two girls went slowly and softly back up to the sky. That night, Ue-nuku sat alone in his house. He said to himself, "Will I ever see the two girls again? They were so beautiful. I want to 15 marry one of them!" While he was thinking, the door of this house opened and the Mist-girl came in. “Ue-nuku, I have come to stay with you," she said. "But I can only stay at nighttime. When day comes, I must go back up to the sky. If the sun shines on me, I will die." The Mist-girl stayed all that night. Before the sun came up, she said 20 goodbye to Ue-nuku and went to her home in the sky. Ue-nuku did not like this. 4[ he/her/him / stay / to / wanted with all the time. One day, he said to himself, "I will put "mats over the door and window of my house. The Mist-girl will not know day has come. 25 She will think it is still night, and she will stay with me." That night, there were mats over the door and window of the house. "Day has not yet come," said Ue-nuku. "Stay with me." The Mist- )! I'm sure it is day by girl said, "What a 5 ( ) ( now." Ue-nuku said again, "Day has not yet come. Stay with me." Time passed, and the Mist-girl said a third time, "This night is too long. I'm sure it is day now." Before Ue-nuku could stop her, she

解決済み 回答数: 1