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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

1.(1)②、(2)②、(3)①、(4)③④⑧⑩、(5)③④⑤、(6)③④、(7)①④⑥、(8)①②③⑥、(9)の解説をして欲しいです。3枚目が答えです

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未解決 回答数: 0
英語 高校生

7行目の文の文構造教えて欲しいです🙏

25 The Maya loved cacao so much they used the beans as currency. They also believed it is good for you which many people still say today about cacao's most famous byproduct, chocolate. 物 In fact, cacao, also called cocoa, which is the not-so-secret ingredient of chocolate, s contains hundreds of bioactive* plant compounds, including flavanols*, which have with numerous possible health benefits. been (あ "Research on the bioactive components of the cacao bean pretty consistently shows that if you're consuming greater amounts of flavanols you see mechanisms (linked to heart disease are, by and large, favorably impacted," says Howard Sesso, an 10 epidemiologist at the Harvard T.H. Chan School of Public Health and Brigham and Women's Hospital. This includes improvements in blood pressure and cholesterol levels. But while cacao does have intriguing potential to boost heart health and brain function, no science supports eating large amounts of chocolate as a health food 15 sorry chocoholics. Here's why. - Spurred by chocolate's popularity, numerous studies have explored how the natural chemical compounds found in cocoa might be good for human health. While some have suggested that less than an ounce of dark chocolate might 本単位 VT improve heart health, much of the research doesn't involve eating actual chocolate not A but rather BAというよりむしろB 20 but rather its components. In 2022, (2) Sesso and colleagues found compelling evidence for the benefits of 説得力のある flavanols. In a clinical trial of 21,000 adults, they found that the half of the group that took 500mg of cocoa flavanol supplements daily had a significantly lower risk of death from cardiovascular disease* than those who had taken a placebo. Flavanols may also boost insulin sensitivity, according to some studies, which might be helpful in reducing the risk of type 2 diabetes. But the results aren't conclusive, and those at risk of diabetes might be () (to choose a cacao-inspired

未解決 回答数: 1
英語 高校生

下線部Dと答え.ウはなぜ同じ用法なんでしょうか 教えてください🙏

closer to reality. Researchers have investigated the use of electricity to stimulate vision for nearly half a century. In the 1960's, a *physiologist implanted 80 electrodes on the surface of a blind person's *visual cortex, a region at the back of the brain. Wireless stimulation of the electrodes made the patient see spots of light known as *phosphenes. This is the first stop for visual signals coming from the eye. (D) By the 1980's, a crop of *ophthalmologists began considering a narrower and seemingly easier-to-solve problem: making *prostheses for the eye. They suggested that degrade *photoreceptor cells called *rods and cones, still leave large portions of the retina intact even after a patient has become totally blind. The way to stimulate the remaining functional cells was proved *feasible in the mid-1990's. A device consisting of a tiny video camera perched on the bridge of a pair of glasses, a belt-worn video processing unit, and an electronic box, was developed recently. The electronic box issues signals to an implant behind the patient's ear that has wires running to a grid of 16 electrodes affixed to the output layer of the retina. The video processor wirelessly transmits a simplified picture of what the camera images to the box, and then the retinal implant stimulates cells in a pattern roughly reflecting that information.

解決済み 回答数: 1
英語 高校生

2のCertainlyからの文構造が分かりません。and peopleとかもう無理です。お願いします🙇🏻‍♀️ 追加追加 and peopleは並列の1番最後ですか!? じゃあ、:はなんですか?毎回毎回どう訳したらいいのか分かりません。

構文・語句解説 第1段落 Language serves many functions. Certainly one of its most common and most important purposes is to help us describe various phenomena, such as events, situationg is to Pheno and people: “What is it?” Another purpose is to evaluate these same phenomena: “Is it good or bad?" 4Typically, we consider descriptions to be objective, whereas we consider evaluations to be subjective. 言語は多くの機能を果たしている。 2間違いなく、最も一般的で最も重要な目的の1つは、 我々が出来事や状況や人のような様々な現象を記述する, つまり 「それは何なのか」というこ とを記述するのを助けることである。 もう1つの目的は, これらの同じ現象を評価する,つま 「それは良いのか悪いのか」と評価することである。 4概して我々は、記述を客観的であると 考える一方で、評価を主観的であると考える。 ■□ certainly 「間違いなく, 確かに」 □ help Odo 「Oが・・・するのを助ける」 □ phenomena < phenomenon 「現象」の複数形。 □ situation 「状況」 □ evaluate 「(を) 評価する」

解決済み 回答数: 2