青チャートI Aです この式変形が、左辺の言っていることはわかるのですが、それをどうしたら右辺になったのかわかりません

62 重要 例題 170 曲面上の最短距離 右の図の直円錐で,Hは円の中心線分ABは直径, 本面 OH は円に垂直で, OA = a, sin0= 1/23 とする。 点Pが母線 OB上にあり, PB= とするとき, a 3 点Aからこの直円錐の側面を通って点Pに至る最短経 路の長さを求めよ。 241038 解答 AB=2r とすると, △OAH で, AH = r, ∠OHA=90°, 1/3であるから=1 sin0= a 側面を直線OA で切り開いた展開図 は、図のような, 中心 0, 半径 OA=αの扇形である。 中心角をxとすると, 図の弧 ABA' の長さについて 2ла• 基本 149 指針▷ 直円錐の側面は曲面であるから, そのままでは最短経路は考えにくい。そこで,曲面を広 げる,つまり 展開図で考える。 側面の展開図は扇形となる。 なお,平面上の2点間を結ぶ最短の経路は、2点を結ぶ線分である。 x 360° = =2πr であるから A a 3 217 a• 2 9 B PSDOCS A' 14814 HAMAS USA.9 X a VMIJA 00000 HO13-JOHA SUSHED THE „HƆA, TƆA ---3---- JOHD AMI EV H r x=360°=360° 1/3=120° a 3 a 3 ここで, 求める最短経路の長さは、図の線分 APの長さである 2点S, T を結ぶ最短の経路 から、△OAP において, 余弦定理により, は、2点を結ぶ線分 ST AP2=OA2+OP²-20A・OP cos 60° =x²+1 + (-1/a)²-2a.. AP>0であるから、求める最短経路の長さは7a S.S S O YB LIGE A(A) AVであ MA 弧ABA'の長さは、底面の 円の円周に等しい。 T

英検準2級の過去問です！！ 添削お願いします🙇‍♀️

ai ライティング ●あなたは、外国人の知り合いから以下の QUESTION をされました。 • QUESTION について, あなたの意見とその理由を2つ英文で書きなさい。 OVID ●語数の目安は 50 語~60語です。 5 ●解答は, 解答用紙のB面にあるライティング解答欄に書きなさい。なお,解答 欄の外に書かれたものは採点されません。 解答が QUESTION に対応していないと判断された場合は, 0 点と採点される ことがあります。 QUESTION をよく読んでから答えてください。 Sysd a car? Many QUESTION api Moyronichinw Do you think it is a good idea for people to have a car? is famou (18) rt museums, and Iniosae JrW udalon elamused show aigeibome of the table next

8、なぜ答えが④になって他の選択肢が❌なんですか？

1 in do not feel 2 through 8. Last year Christmas day ( 1 set on 2 hit on A of on (X*5) TC 1 1. 3 away ) Saturday. 3 happened botsent \ boeutsdt basket (4) out 4 on fell or gnisd\ ai don\ s 6.1. 1 1

未来形についてです。 解説お願いします。

FUTURE FORMS 5 Match the future forms with the writer's purpose. 1 Are you going to the rubbish tip? I'll go with you. Cobur? 2 Satoshi is going to give a presentation about global warming.e 3 On Thursday, leaders are meeting to discuss climate change. 4 Some scientists say sea levels will rise in the next ten years.b YRATURA 5 The four warmest years have occurred since 2014. Scientists think temperatures are going to continue to increase. a fixed arrangement for the future vabimud ab soqqalb dulonso omosedus b prediction about the future c decision made at the time of speaking d future event when there is evidence e decision made before speaking abssd own thiw slane ciertvinu deinn 1. sila ten

FLEX2 レッスン3 教科書のcompressionが分からなさすぎてヘルプです

Choose the appropriate answer. hartan art ell 1. It became more important for people to get salt a. when Roman soldiers were given money to buy it b. when people started to hunt animals for food c. when people ate less meat and began to eat more grains and wheat 3. The influences of salt can be seen a. in modern cultures b. not in languages but in customs and religions c. more in languages than in customs or religions boyasdo 2. What ancient people discovered was a. that salt could stop droughts and help people survive a lack of food b. that salt helps bacteria grow foods c. that salt keeps foods from going bad 4 4. Thanks to some discoveries by scientists, a. people have changed how they produce salt b. people have begun to use salt in new ways edme c. people have found that salt has always had an influence on many cultures Salt is 1 dor d blues 2 Fill in each blank with the most appropriate word to complete the summary. EXTER Jika ODOY velg avs ) for our lives and we cannot live without it. In ancient times, as people be eat more food which were low in salt, they needed a lot more salt to survive. Eventually it bec 2 3 ) trade item. Also, salt was used to ) famines and travel to ) food. Because of this, people 5 ancient people, has also 6 ) places. Salt, which was very importa modern cultures. Some used, and its influence can also be found in some ) related to salt an 8 ). One important scie 9 ) enabled people to produce new things. Salt is now a common item, but it has had ) on the world. 10 7 affected / available / decrease / discovery distant expressions impact / precious / preserve / religions essential survive

英検2級のライティングなんですけど、私の回答を採点して頂きたいです。文法的に間違っているところやスペルミスなどお願いします🙇‍♂️

No. Date I think that the number of these people will increase in the future. I have two reasons. First. It is bad for young people to start working for large companies. They have to work for a long time so they have a lot of stresses Second, young people work for a long time but they aren't. C got the income so the large companies should get a lot of 69 Incomes. That is why, I think that the number of these will increase in the future. (84) 45

見にくいですが、1.の答え合わせと、2の回答を教えて下さい。

1 Complete the sentences with a, an, the or no article (-). 1 Is there a hotel? my bus to the airport from 2 Our centre is equipped with the latest facilities. 3 How long have you been learning to speak ____ Chinese? 4 Could I have a cup of tea, please? 5 Sorry, but he isn't at _____ work today. 6 A main exhibition centre is over there. 7 He's a person I mentioned during dinner. You should meet him. 8 Is this an information you wanted? 9 What time's my flight to the USA? 10 I normally travel by a bicycle. 11 I love the vegetarian food. 12 The greatest innovation of twentieth century was the Internet. 13 Are we meeting again on the Thursday? 14 Hi. My name's Elaine Keevey and I'm an accountant. 2 Read eight rules and guidelines for staff working at a conference centre. Add the correct article(s). the 1 All staff must be polite and helpful to trade fair delegates. 2 Remember to wear ID badge at all times. the 3 Check visitors' names on registration list when they enter main venue. 4 If you see visitor who looks lost, immediately offer to help. 5 Staff not wearing uniform will be sent home. 6 Exhibition centre is always closed to visitors on Mondays. 7 For information, direct visitors to Central Registration Desk. 8 If you travel by car, please park in Staff Car Park.

ベクトルの問題です。解説お願いします！

NL SA (座標空間における4点O(0.0.0).A(J21)、 B(0.3.0), c(-1.0,VB)について次の問いに答えよ! 3 2点PQは、S≧0,+30,5+20=3となる山に 対し、SDAQを満たすものとする。△ opaの面積が最大になるとき、四面体Opecの体積を 求めよ。 203× F x TV 3√14 2√y.

ベクトルの問題です。難しいので教えてください。

NL SA (座標空間における4点O(0.0.0).A(J21)、 B(0.3.0), c(-1.0,VB)について次の問いに答えよ! 3 2点PQは、S≧0,+30,5+20=3となる山に 対し、SDAQを満たすものとする。△ opaの面積が最大になるとき、四面体Opecの体積を 求めよ。 203× F x TV 3√14 2√y.

これの範囲の設定の仕方を教えてください！！

LICA" 7 1 + = + = + = + = 2 > log(n+1) したがって P.247 練31 次の不等式を証明せよ。(nは2以上の自然数) 1 + 1 =1/1²/1 + 1 =1/1/2 + +w+ // < 1 + logn 証明) 自然数㎞に対して、R-1≦X≦Rのとき 1 { // また、等号は常に成り立たないので k S & dx < Sdx < したがって k po & dx RY X n≧2のとき k R=2 URT 12 5-² - x + 1 よって 巻 - dx = S₁ -dx 1 / + = + & dx +w+ No. Date ·dx+ ++ [tete da = S₁ & 2 dx = [loglal]," = logn // < logn n 1 + 2/² + 1 ² + ² + √// < 1 + logn n