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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
数学 大学生・専門学校生・社会人

多様体を構成するために、位相空間に完全アトラスを導入するところで質問です。 完全アトラスを導入するメリットとして、この文章の下線部を「異なる座標系を用いたのに同じ計算ができてしまうという問題が解消される」解釈したのですが、そこがよくわかりません。座標系を変えて計算する... 続きを読む

1 Two n-dimensional coordinate systems & and ŋ in S overlap smoothly provided the functions on¯¹ and ŋo §¯¹ are both smooth. Explicitly, if : U → R" and ŋ: R", then ŋ 1 is defined on the open set ε (ur) → ° (UV) V and carries it to n(u)—while its inverse function § 4-1 runs in the opposite direction (see Figure 1). These functions are then required to be smooth in the usual Euclidean sense defined above. This condition is con- sidered to hold trivially if u and do not meet. Č (UV) R" Ĕ(U) n(UV) R" S n(v) Figure 1. 1. Definition. An atlas A of dimension n on a space S is a collection of n-dimensional coordinate systems in S such that (A1) each point of S is contained in the domain of some coordinate system in, and (A2) any two coordinate systems in ✅ overlap smoothly. An atlas on S makes it possible to do calculus consistently on all of S. But different atlases may produce the same calculus, a technical difficulty eliminated as follows. Call an atlas Con S complete if C contains each co- ordinate system in S that overlaps smoothly with every coordinate system in C. 2. Lemma. Each atlas ✅ on S is contained in a unique complete atlas. Proof. If has dimension n, let A' be the set of all n-dimensional coordinate systems in S that overlap smoothly with every one contained in A. (a) A' is an atlas (of the same dimension as ✅).

未解決 回答数: 0
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