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数学 大学生・専門学校生・社会人

確率の勉強をしている学生なのですが、この問題が分かりません。どなたか教えていただけませんか。

練習問題 1.8 (積率母関数) X を非負の確率変数とし, x(t) = Eetx は全てのt∈ に対して有限であると仮定する.さらに,全てのt∈ R に対し E [XetX] < ∞ であると仮定する.この練習問題の目的は, '(t) = E [Xetx] で あり、特に'(0)=EX であることを示すことである。 微分の定義, すなわち次式を思い出そう. 4'(t) = lim x(t) - (s) lim st t-s st EetxEesx t-s 「etx = lim E st t-s 上式の極限は,連続な変数sについて取っているが,t に収束する実数列{8}n=1を 選ぶことができ, 次を計算すればよい. 「etx e³n X lim E sn→t t-Sn これは、次の確率変数の列 etx -enx Yn = t-Sn の期待値の極限を取っていることになる.もしこの極限が, t に収束する列{Sn}=1 の選び方によらず同じ値になるならば、この極限も limotE [ex と同じで,そ れは '(t) である. .tx sx ← -e t-s 解析学の平均値の定理の主張は,もしf(t) が微分可能な関数ならば、任意の実数 s ともに対し,stの間の値の実数0で次を満たすものが存在するというものである. f(t)-f(s) =f' (0) (t-s). もしweΩを固定し,f(t) = etx(w) を定義すると,この式は, etX(w)_esx(w)=(t-s) X (w)e (w)x(w) (1.9.1) となる.ただし,(ω) はωに依存する実数 (すなわち,tとsの間の値を取る確率変 数)である. (i) 優収束定理 (14.9) (191) 式を使って,次を示せ. lim EY = Elim Yn=E [XetX] . (1.9.2) n→∞ [n→∞ このことから,求める式 4'(t) [XetX ] が導かれる. (ii) 確率変数 X は正の値も負の値も取り得、全てのt∈Rに対し Eetx < かつ E [|X|etX] < ∞ であると仮定する。 再度 '(t) = E [XetX] を示せ(ヒント: (1.3.1) 式の記号を使って X = X + - X- とせよ . )

未解決 回答数: 1
英語 中学生

根気強く英文読める方お願いします🙏 この問題の(2)は合っているでしょうか。 違うのなら違う理由も教えてくれるととても嬉しいです😭お願いします

TREK [3] 9分 10 2935 受験 難問 次の英文を読んで、あとの(1)~(3)の問いに答えなさい。('13 神奈川県) Brian is a high school student from America. He joins a *volunteer club at school. Last Sunday he went to a "nursing home with his friends to teach the old people living there about computers. Mr. Doi, one of the old people there, is talking with Brian in a room at the nursing home. sdgoon 5 Mr. Doi: Hello, I am Kazuo Doi. Nice to meet you. Thank you for coming today. Nice to meet you, too. My name is Brian. What can I do for you, Mr. Doi? Brian Mr. Doi: Can you teach me how to send e-mails, Brian? Brian Mr Doi : Brian Of course, I can. Do you want to send an e-mail to anyone? Yes. One of my friends lives in a nursing home in Hokkaido. I have not seen her for a long time, but she sent me a "postcard last summer. She wrote her *e-mail address on the postcard. I want to send her an e-mail to say "Hello," but I don't know how to do it. salad : Don't worry, Mr. Doi. It is not difficult to send an e-mail. Tellsafi Two days later, Brian and his friend Yumi are talking in their classroom. 15 Yumi Brian Yumi Brian : 20 Yumi : Brian, I hear you went to a nursing home last Sunday, right? : Yes. I went there to do *volunteer work with my friends. : That's great. What did you do there? odon of d We taught the old people living there about computers. They were very glad to learn how to use computers. What did you teach them about computers? I taught some old people how to send e-mails. Mr. Doi was one of them and Brian : his English was good. Read this e-mail from him. He sent it to me yesterday. Brian and Yumi are reading the e-mail from Mr. Doi. Hello, Brian, 100 living here enjoy it. I am sending this e-mail with a picture of me *in front of a microphone." Her e-mail was *encouraging to me. Now I have found an important thing to me. It is to try new things. When I find a new thing to try, I will send you an e-mail again. 35 Kazuo Doi After reading the e-mail from Mr. Doi, Yumi and Brian are talking again. Yumi Mr. Doi enjoys *communication by e-mail. Brian Yes. I'm very happy to hear that. Yumi You did a good thing, Brian. 40 Brian Yumi Brian 45 Yumi : Brian Yumi 50 Brian Yumi 55 Brian T Thank you for coming last Sunday. Do you remember my friend who sent me a postcard with her e-mail address? After I sent her an e-mail, she sent me an e-mail back soon. Using e-mail is a lot of fun. In her e-mail she said, "Now I am trying a new thing in my nursing home. I am *in charge of an announcement over the PA system for 10 minutes in the morning. During this time, I read the *newspaper of the day and make some *comments. Many people Yumi Thank you, Yumi. I went to the nursing home to teach the old people there about computers, but I also learned something there. : What is it, Brian? Mr. Doi knew his friend was in charge of an announcement over the PA system, and then he started to think about trying a new thing, too. I know. Mr. Doi says, "encouraging" in his e-mail. Right. When I taught him how to send e-mails, he said, "I have wanted to learn a lot of things. Using e-mail is one of them." I see. You want to say the e-mail from his friend made him more *positive, right? That's right. First, Mr. Doi learned how to send e-mails and wrote an e-mail to his friend. Next, he got an e-mail from his friend and knew his friend was trying a new thing. Now Mr. Doi ( ) to him. Mr. Doi thinks that it is to try new things. We can say it is good to know how our friends are doing. It is wonderful to *communicate with other people, Brian. : I think so, too. Communicating with other people can make people more positive. I learned that from volunteer work in the nursing home. : I hope that Mr. Doi can find a new thing to try. Please tell me when you get an e-mail from him again. (注) volunteer club ボランティアクラブ nursing home 老人ホーム send〜 〜を送る postcard 絵はがき e-mail address 電子メールアドレス (約 685 語) volunteer work ボランティア活動 in charge of an announcement over the PA system 館内放送を担当して comments コメント in front of a microphone マイクの前の communication by e-mail 電子メールによるコミュニケーション communicate with ~ ~とコミュニケーションをとる newspaper encouraging 励みになる positive 前向きな

解決済み 回答数: 1
英語 高校生

ピンクで囲んだ部分のdestroyingとforcing、makingが何故ingが着いているのか分かりません😿分詞構文でしょうか?

You are preparing a presentation for the school science club, using this article from a scientific website. Reaching a Tipping Point: What to Do About the Problem of Space Junk? For over fifty years, slowly at first, but with increasing intensity, we've been sending objects up into orbit. Most of these items begin life as useful 使節を開始する有用な devices, such as the thousands of satellites that bring us information and give 装置として us our 21st century communication, but even these eventually fall out of use 結仕 使われなくなる or break. These satellites, living or dead, share an increasingly crowded layer, 混雑した層 known as near-earth orbit, with rocket parts, tools, and pieces of metal from objects that have already crashed together and broken into pieces. 粉々になる ?? This garbage poses a threat both (to working" satellites of which there are thousands), and (to the earth itself.) For example, in 2009 a disused Russian 使われなくなった module crashed into an active US satellite) destroying both and forcing the International Space Station to change course to avoid the thousands of broken ためらう pieces. While most junk that falls back to earth burns up in the atmosphere. 大気圏上空で larger chunks can occasionally hit the ground, posing a threat to people and Pieces that do burn up] leave pollutants in the atmosphere, such as Property aluminum particles, which can destroy the ozone layer アルミニウム 粒子 It's clear that removing space junk is vital if we are to maintain and build upon our current satellite network. The problem has been discussed continuously since the 1970s, when Donald Kessler, a senior scientist at NASA 継続的に described a scenario (later known as Kessler syndrome) (where a runaway 制御不能の others more and more likely. While the 2009 incident may be the first large cycle of collisions begins, with each collision creating more debris, making 衝突のサイクル near-earth collision, it is thought that Kessler syndrome has already begun with smaller objects. Since Kessler syndrome was first described, many solutions have been proposed, from using lasers to robotic garbage collectors, but cost has been an obstacle to most. In 2021, a Japan-based company named Astroscale launched ELSA-d (short for "End-of-Life Services by Astroscale Demonstration") to show

解決済み 回答数: 1
英語 高校生

緊急です! この1ページの答え教えてください🙏

(教科書 pp.52-59) Unit 4 Is your city sustainable enough? star n = 1. The Can- Do! Speak 都市問題について聞いた情報をもとに説明することができる。 都市問題を解決する方法について議論することができる。 Write 自分の住む地域の自治体に要望書を書くことができる。 Small Talk 4) How is the building in this picture different from an ordinary house? Do you think your town is comfortable for you and people of all ages? banihobnu Listen ai "but won" ansom bidro coll Riko and her cousin Yuri are talking online (Yuri is now a college student studying in Vauban, Germany). Listen to the conversation and fill in the blanks. Riko col mont hio daw blow ch Vauban Buildings: ⚫designed to consume less [ Cars: .2[ ]% of the residents: don't have a car the public transportation service ⚫not allowed to [ ] in the residential areas children: play safely in the [ ] Yuri is related Listen Again 1) Listen again, and fill in each blank below. 2) After that, choose one similar expression from (a) to (c). Communication Strategy ① 久しぶりに会った相手にかける言葉は? Riko: Hi, Yuri. How's your college life in Germany? (c) What's up? pane (a) It's a pleasure to meet you. (b) Long time no see. Communication Strategy ② 話題にさらに論点を加えるには? Yuri: Trams run every seven minutes along the main road, and residents have easy access to the stops. so that children can play safely in the streets. (a) Finally cars are not allowed to park in the residential areas (c) On top of that (b) In other words Sp You (@ in the wor haring ex 4210. and th Mbuisn Expla de6 eftor

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