BEはBAのBO上への正射影ベクトルであるから～の説明がわからないです。教えて頂きたいです。

EX 056 座標空間において,原点を中心とし半径が5の球面をSとする。点A(1, 1, 1) からベク トル(0, 1, -1)と同じ向きに出た光線が球面 Sに点Bで当たり,反射して球面Sの点C に到達したとする。ただし, 反射光は点 0, A, B が定める平面上を, 直線 OBが∠ABC を二 等分するように進むものとする。 点C の座標を求めよ。 [早稲田大] 球面Sの方程式は x2+y2+z2=5 B 与えられた条件から,正の実数を用いて. A OB=0A+AB=0A+ku=(1,1+k, 1-k) E と表される。 D よって, 点Bの座標は (1, 1+k, 1-k) 点Bは球面S上にあるから 1+(1+k)+(1-k)=5 C

解説でBE＝2/5BOとなっているのですがどこからそれがわかったのかわからないので教えて頂きたいです。

5555 EX 56 座標空間において, 原点0を中心とし半径が5の球面をSとする。 点A(1,1,1) からベク トル = 0, 1, -1)と同じ向きに出た光線が球面Sに点Bで当たり 反射して球面Sの点C に到達したとする。 ただし, 反射光は点 0, A,Bが定める平面上を, 直線OB が ∠ABC を二 等分するように進むものとする。 点C の座標を求めよ。 [早稲田大 ] 球面Sの方程式は x2+y2+22=5 B 与えられた条件から,正の実数んを用いて, A OB=0A+AB=OA+ku= (1,1+k, 1-k) E と表される。 D よって, 点Bの座標は (1, 1+k, 1-k) 点Bは球面S上にあるから 12+(1+k)+(1-k)=5 C

この英検準一級の英作文を添削してください🙇‍♀️ よろしくお願いします！

f X フリートライ Write an essay on the given TOPIC. Use TWO of the POINTS below to support your answer. Structure: Introduction, main body, and conclusion ◆ Suggested length: 120-150 words 完全無 ライティ 実力を フリー B! TOPIC > i Agree or disagree: Movies and TV programs have more negative influence than positive on how young people behave. 詳しく Cost Society Entertainment Culture

至急！！ 英検二級のライティングをどなたか添削して頂けないでしょうか！どうかお願いします！また、この文だと何割ぐらい取れそうかも教えて頂けると嬉しいです🙇 補足　×This essay will have → ⚪︎This essay will explai... Read More

TOPIC Today in Japan, many buildings and public areas have a lot of lights for decoration, such as the lights used during Christmas. Do you think this is a good idea? POINTS • Safety • The environment • Tourism

写真 2枚目の 英文のshooting apart は、jetのことなんでしょうか？ 日本語訳は写真の枚数的に後半しか写せませんでした。ちなみに疑問点の和訳は赤で線を引いているところです。

Ⅱ 英文を読み、下記の問いに答えなさい。 (7) Like a tiny submarine, the chambered nautilus speeds through the ocean on little jets that it creates by sucking in water and spitting it out. However, as ways of movement go, jet propulsion is not usually a (8) very good use of energy. In the ocean's depths where oxygen gets thin, the nautilus seems to be putting itself at risk by expending so much effort on movement. Fish use far less energy by pushing at the water with their fins. So how does it manage to jet around unscathed in the ocean's depths? Graham Askew, a biomechanics professor at the University of Leeds, set out with a graduate student, Thomas Neil, to understand better how this shellfish moves. They found that the nautilus is actually a (9) highly efficient jet-propelled creature, wasting much less energy than

(1)S2nの丸で囲まれてる箇所はどこから導いたものですか？

基本 例題 432通りの部分和 S2n-1, S27 の利用 無限級数1- + 1 1 1 1 18 + + 2 2 3 3 4 4 00000 ① について について (1)級数①の初項から第n項までの部分和をSとするとき, Szn-1, S2n をそれ ぞれ求めよ。 (2) 級数①の収束, 発散を調べ, 収束すればその和を求めよ。 指針 (1) S2-1 が求めやすい。 S2n は S2n=S2-1+(第2項)として求める。 基本42 (2) 前ページの基本例題42と異なり,ここでは( )がついていないことに注意。 このようなタイプのものでは,Sを1通りに表すことが困難で, (1) のように, S2n-1, S2n の場合に分けて調べる。 そして、次のことを利用する。 [1] limS2-1= limS2n = S ならば limS=S n→∞ n→∞ [2] lim S2n-1≠lim S2 ならば n→∞ 818 818 {S} は発散 1 1 (1) S21=1- + 1 1 + 2 2 3 3 4 解答 == =1-(12/2-1/2)-(1/13-1/3)- 4 1 n + 1 ? n -(-1/2) =1 1 1 S2n=S2n-1 x+1 n+1 (2)(1) から よって したがって, 無限級数 ① は収束して, その和は1 n→∞ 81U limS2n-1=1, limS2n=lim1 n→∞ limSn=1 n→∞ n+1 =1 部分和 (有限個の和) なら ( )でくくってよい。 [参考] 無限級数が収束す れば,その級数を,順序を 変えずに任意に() でく くった無限級数は,もと の級数と同じ和に収束す ることが知られている。 75

2段落目の2行目についてです。 和訳を見たところ、ミカル シュワルツの研究に基づいて設立された、とあります。 ここで、"基づいて "は英文中のfound onのことなんでしょうか？

11 脊髄再生医療 英文] 11 It was a miracle of almost biblical proportions. In 1998, scientists in Israel revealed that rats whose spinal cords had been severed had called walked again after an injection of healing immune cells macrophages. Their hopes buoyed by enthusiastic media coverage, = paralysed patients began to dream of taking their own tentative steps. 12 Five years on, the status of those dreams remains unclear. Proneuron Biotechnologies, a Los Angeles-based company founded on the back of the research of lead investigator Michal Schwartz at the Weizmann Institute of Science in Rehovot, is expected soon to release the results of an initial trial of the procedure on eight patients with spinal injuries. Media reports have indicated that some patients have recovered some feeling and movement, but many researchers do not expect a repeat of the rodent miracle. Indeed, they claim that at least one group has since tried, and failed, to reproduce Schwartz's original animal results.

英検準2級の英作文の添削をお願いしますm(_ _)m Do you think it is good for elementary school students to have smartphones? Yes, I think so. I have two reas... Read More

この英語長文において、印刷技術の発達に必要な技術はどのようなものであるか50~200字で答えてください

木版画 鋳造 第3問 以下の文は、 S. Strandh の “Machines, an illustrated history" からの抜粋で ある。 次の文を読んで、設問に解答せよ。 (ア) The tools of precision mechanics were, without doubt, the technical pre conditions for making wood cuts and for the development of printing. The oldest dated wood engraving is from 1418. It shows fine lines throughout 細部 and a richness of detal, which imply that the tools used, the knives, burins, and so on, must have been eminently suitable At this time, it was only the precision mechanics of clock making which could achieve the technique required for such tools. 精密機械技術 (イ) A (woodcut was produced by transferring a drawing, reversed from left to right, onto a carefully surface-ground "block" of wood, after which the surface wood on either side of each line in the drawing was cut away with a burin of forged steel. The remaining wood on all 'surfaces which were to be white in the drawing were then cut away with gravers and gouges, so that the lines of the drawing became raised. They were then inked and pressed against paper. これは 理由では ないから、 (~のときに、何 が原因か は不明) The woodcut method spread rapidly in the late Middle Ages when pictures were rarity. At first, skilful craftsmen made the woodcuts, but before long, eminent artists were themselves cutting their own drawings in wood. One of the first was the German Albrecht Duerer (1479-1528) who, in 1498, published the famous pictorial series of the Revelation of St. John. Graphics had become an independent art form-based on the progress of precision 酒の mechanics! 可動式の The 1440s saw the first book printed with movable die-cast type. (The letter press printing method used by Johann Gutenberg (1399?-1468) was basically the same as the one used for printing woodcuts, but Gutenberg used cast, movable type instead of cut blocks. The production of dies for the type was made possible by the tools of precision mechanics, too. It does not detract from Gutenberg's contribution that printing with movable type has been practised in the Far East, or more specifically Korea, two thousand years prior to this. Several of the techniques described here, which developed so quickly during the technical revolution of the Renaissance, had had predecessors in other parts of the world. ' 金楼 にねじ を刻む 道具 ~をなら K あったもの

Tocqueville's concern, to a large extent, became a reality. In the process of creating a land of abundance, Americans began to judge them... Read More