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数学 高校生

この問題なんですが Pを x、Y、0遠いて計算して 出すというのでは答えが違うのはなぜなんですか? 字が汚くてすみません。

-118 Think (686) 第11章 空間のベクトル 例題 C1.60 空間における交点の座標(2) **** 2点A(5, 0, 9), B(1, 4, 3) と xy 平面上を動く点Pに対して, AP+PB の最小値と,そのときの点Pの座標を求めよ. 同じ側 ABS ・平面 考え方 2点A, B が xy 平面に関して反対側 にある場合, AP + PB が最小となる のは, 3点AP Bが一直線上にあ る場合である。 同じ側にある場合は, xy 平面に関してBと対称な点B' をと ればよい 反対側 AS P xy 平面 ・B B' 直線の方程式をベクトル方程式で考えて, 媒介変数表示する。 Abs 2点A, B を通る直線のベクトル方程式は OP=OA+tAB である=10 解答 2点A, B は xy 平面に関して同じ側にある. xy 平面に関して点Bと対称な点をNHAT もに正なので, B'(1, 4, -3) とおくと, PB=PB' より, AP + PBが最小となるのは, 3点A,P, B' が一直線上にあるときである. AB' = (-4,4,-12) より, OP=OA + tAB' =(5,0,9)+t(-4,4,12)x =(5-4t, 4t, 9-12t) A,Bの座標がと xy 平面に関して同じ側 にあるとわかる. 直線 AB'′ と xy 平面 15 P B' y の交点が求める点P である. 9 したがって、点Pの座標は, (5-4t, 4t, 9-12t) ・① 013+8 点Pはxy平面上の点より 座標は0だから, 9-12t=0 t=- 3 このとき,P(230) 2-)-A2AO HO (S) 50-RO-1 よって,P(2,30) のとき,AP+PBは最小となり AP+PB=AB、 =√√(-4)'+4°+(-12) =4/11 (3 tを①に代入する. Focus 直線のベクトル方程式 OP = OA+tAB =OA+t(OB-OA) =(1-t)OA+tOB 10-010

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英語 高校生

問4の(2)についてです 私は(2)に「先生を思い出す」と言う意味でウを選んだのですが、答えはアでした。なぜウだと不適なのか教えていただきたいです🙇🏻‍♀️😭

(配点 23) Everyone wants to do well on tests. Here is some advice from successful students on how to do well on tests. Listen to the teacher from the first day of class for hints about what is important. For example, the teacher will emphasize the important information by repeating it or telling you it is important. When you look over your textbook and notes again, you should already know what is important. After each lecture, look over your notes again. Come to class ready to ask questions about what you don't understand. C Look at the visual aids the teacher uses. For example, if the teacher asks you to look at a diagram or graph in your textbook, make sure you understand why that diagram or graph is important. There may be a question on the test that asks about that diagram. Study for an essay exam. Students who prepare for essay exams do better on all types of exams. Students need to know more information for essay exams than for true/false or short-answer exams. There are no hints on the exam itself, so students must learn more for essay exams. To prepare for an essay exam, always read the *material twice before you start taking notes. When you read the material the first time, it may seem difficult. When you read the material the second time, it will seem easier. This is similar to when you (1) have to find the way to a friend's house for the first time. The second time you go to your friend's house, it's easier because you know the way. It may even seem shorter because you don't have to slow down as much to check street names or landmarks. The same is true with the material you read. The second time you will already know the words and ideas. In China, they lp to stop de After you've read the material twice, take notes. At this point, you'll find that you know some of the material and can focus on what is most important. Don't ignore *footnotes in your reading. Sometimes teachers think the information in a footnote is important and will ask a question about it. Write down the important information in is in the years t your notes. After you take notes, go back and add your opinions to them. Write down For food in the desert. the ideas that you agree with and the ideas that you disagree with. People remember ants ex large number

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