接平面の方程式の問題なのですがわかる方教えてください。途中式もあると助かります。

{} ${(x)8) (4) f(x,y)=x2-y2 のとき,曲面z = f(x,y) 上の点 (Opt (1, 1, f(1,1)) における接平面 :)a}

本文2行目のplacing って何を意味しているのでしょうか？ 教えていただきたいです！

次の英文 [A][B] [C] の内容に関して (27) から (38) までの質問に対して最も 3 適切なもの、または文を完成させるのに最適切なものを1.2.3.4の中から~ C [A] From: Noel Lander <noel@coffeeshopsupplies.com> <thedaydreamcoffeeshop@goodmail.com> To: Gary Stein Date: June 5 Subject: Your order Dear Mr. Stein, Thank you for placing an order by telephone with Jenna Marks of our sales department this morning. The order was for 500 medium-sized black paper cups with your café's name and logo printed on them. According to Jenna's notes on the order, you need these cups to be delivered to you by Saturday. I am sorry to say that we do not have any medium-sized black coffee cups at this time. What is more, the machine that makes our coffee cups is currently not working. The part that is broken was sent for repair the other day, but it will not be returned to our factory until Friday. Because of this, I am writing to you to suggest some alternatives. If you really need black cups, then we have them in small and large sizes. However, I guess that size is more important than color for you. We have medium-sized coffee cups in white, and we could print your logo on these instead. We also have medium-sized cups in brown. We are really sorry about this problem. Please let us know which of these options is best, and we'll send you an additional 50 cups for free. Our delivery company says we will need to send the order by Wednesday so that it arrives by Saturday. Please let me know your decision as soon as you can. Sincerely, Noel Lander Customer Support Coffee Shop Supplies

6行目のas cassina was knownのところなのですが、どうしてこの形になっているのでしょうか？元の文の形も教えていただけると嬉しいです。

O Cassina With its rich, dark color, caffeinated kick, and roasted aroma, cassina, beverage made from the leaves of a type of holly tree, could easily be mistaken for black tea. Cassina, however, does not come from China, where tea originated, but from the southern coastal areas of North America. Native Americans began drying and roasting cassina leaves over a thousand years ago, and trade in the "black drink," as cassina was known, stretched across the continent before the arrival of European colonizers. The colonizers, too, adopted the beverage, drinking cassina daily in Florida and other southern colonies. 2 severage D 01 importers of black

有機化学の問題です！ どう解けばいいのかわからないので教えてほしいです！よろしくお願いします！

400℃, 石油化学工業では、ナフサの分解で得られたアルケンが、様々な化合物の原料 35気圧で,一部がエチレンと2-ブテンとなり,式(1) で表される平衡状態になる。 として重要である。そのうちの一つであるアルケンAは, 触媒の存在下 第3問 次の文章(A・B)を読み、 問い (問1~6)に答えよ。 [解答番号 17 (配点20) A この可逆反応は, 化学工業の原料として, これらのアルケンの生産量を調整する ために用いられている。 A CH2=CH2 + CH3-CH=CH-CH3 8 12 エチレンは化学工業の原料として重要である。 エチレンを塩化パラジウム(II) PdCl2と塩化銅(II) CuCl2 を触媒として空気酸化することで, 化合物Bが得られ る。この方法は、エチレンのワッカー酸化とよばれる。 2 B パイナップルに似た果実臭のする液体で, 溶剤としてよく利用される化合物 C は,工業的には,B二分子から触媒を用いて合成される。 C Cは, 実験室的には,Bを還元して得られるアルコールと,Bを酸化して得ら れるカルボン酸の混合物に,濃硫酸を加えて加熱することで合成される。 2-ブテンからは,合成ゴムの原料として重要なブタジエンがつくられる。また 2-ブテンのワッカー酸化で得られる化合物Dは,溶剤や樹脂の硬化剤として用 H₂02 られている。Dは,2-ブテンに触媒を用いて水を付加させて得られる化合物 酸化することによっても合成される。 Appit 0

写真中の1番下の行にあるas〰︎︎asのところは副詞節として働いているのでしょうか？？

doctors are more へ変更を考えない When I faced circumstances involving end-of-life choices, I adopted the that 取った 手段(方法) 提示する だけ approach of laying out only the options that I thought were reasonable 形妥当である as early in the process as possible. When patients or families brought of (主格だから) 素人

自由英作文の添削をお願いしたいです！ できれば他の表現だったたり、自由英作文のことだったりいろいろ聞きたいです！ お願いします🙇‍♀️

英語の早期教育 a It is true. be an idea that the calier people start to learn However there way foreign languages, the better they require it : this idea I disagree with carly English education own misses the fact that they should prioritize requiring +². foreign language Ever junior high school longuge than students and high school students how difficulty studying Conguage. Je, early English education should not be adopted. a o

汚くてすみません！ この問題の添削をお願いしたいです！！

I disagree that Big companies u have a positive effect on society. I have two reasons. I 4 the environment to producet Large-scale products. Big company mode a lot of products , so they use maturials such as water, electric and gos@ Also, they discharge carbou dioxide. By doing so, global warming will be increasing. Seally worker is difficult to protect @ Nork-life balance. Big companies ask them for many job iro home go they will go @ a at late night. Also some poode have to move their house for working. They will lose their free time, and tell.. tired. Therefore, big companien have a lot of pod points. I think people should work widdle or small companies than big companies, and goople will C C

(21)の答えが3になるのがなんでか少し分からないです…わかる方いますか？？

(21) (22) (23) Any Change? Long ago, humans did not use money. Because they often could not produce everything that they needed, they traded some of their goods for goods made by others. Gradually, the goods that they exchanged were replaced by cash. For hundreds of years, metal coins and paper bills that can be exchanged for goods and services have been produced. Cash is convenient for many people because it is easy to carry. At the same time, though, it ( 21 ). Another disadvantage is that criminals have been able to produce fake coins and bills. In the middle of the 20th century, plastic credit cards were introduced. They had security features to prevent them from being used by anyone except their owners. At first, their use was limited to wealthy people. Over time, however, they became ( 22 ). In the last few years, apps for smartphones that can be used in the same way as credit cards have also become popular. Because of this, some people are suggesting that we may soon see the end of cash. Supporters of a "cashless" society in which all payments are made electronically argue that it would have several benefits. For example, people would not have to worry about keeping their wallets safe. However, some people are concerned that they might be unable to pay for the things they need because of a software error or a broken smartphone. Moreover, some people do not have bank accounts or credit cards, so their only option is to use coins and bills. ( 23 ), it seems as though societies will continue to use cash. 1 can be lost or stolen can be recycled 1 thinner and lighter 3 harder to use 1 For now 2 Until then 2 4 2 4 3 is used for shopping online is understood by almost everyone more colorful and exciting more widely available With luck 4 By contrast

mathmaticaを使ってvan der pol方程式のシュミレーションをしたいのですがグラフが出ないです。どなたか訂正箇所がありましたら教えていただきたいです。

anderpol.m Syntax: (cannot be followed by x, t). 0)= Plot[{x-x^3/3-y}, {t(2x−y)}, {×, −2, 2} {y, −2, 2} {t, 1}] Plot: Options e

また中1理科の光です😭1枚目の写真の（7）の問題に疑問があります。答えが全反射なのは分かるんですが、「角Dが90°をこえるとき、光はすべて反射する」という所が理解出来ません。2枚目の写真に図を載せてあるので角D見て欲しいです。中間流石に焦ってますお願いします🥹

入ったコップの底にあるコインがZ 点に浮き上がって見えた。 Y点から 出た光がX点に届くまでの光の道す じをかきなさい。 (7) の3のように, 角Dが90° をこ えるとき, 光はすべて反射する。 こ のように光がすべて反射することを 光の何というか。できるかつ □ (8) (7)が利用され, ガラ図4 光通信のケ 3 原付 スやプラスチックの繊 43 H 信のケ Z Y