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英語 中学生

問題の2、4、5を教えて欲しいです。よろしくお願いします🙇‍♀️🙇‍♀️

5 Unit 4 長文問題 もしも時間を戻せたら? Target ①関係代名詞 ②仮定法 間接疑問文 1 Do you ever wish you () ( () able to change the past? If you did do all had (2) that ability, maybe you would spend more time practicing soccer, learn the instrument that you always wanted to play, study harder for that big test, or try to save more money for the future. 2 What would you do if you had the ability to turn back the clock? This was a question (あ) which Mr. Woodall, a high school teacher in Philadelphia, asked his students. Mr. Woodall wanted to know what was important to his students but was pleasantly surprised to see the results. I think their answers will be very interesting to you, too. 3 Mr. Woodall expected to see answers (1) which were connected to the own good of the students, but (3) he was wrong. The majority of the which he received from his students were for the good of answers (5) others. 4 A very common answer he found was," If I could turn back the clock, I would take back some things that I said to a friend." Apparently, many of the students regretted saying something (5) ( ) hurt their friends and wanted to change that. Surprisingly, close to 40% of the students answered this way. Another common answer was about pets. “(6) If I were able to turn back the clock, I would spend more time with my dog,” or “(7) I would be nicer to my cat,” were some common answers. Almost 25% of the students missed their pet very much and wanted to show more love. These pets included dogs, cats, birds, rabbits and other animals. 6 There were other answers about reading more books, studying harder, or eating less junk food. However, Mr. Woodall was quite impressed with his students and their concern for others. He decided to share all of the answers with his students, and the students enjoyed hearing the different answers. Mr. Woodall decided to try this activity with his students every year. By asking, he felt he would learn a lot about his students. turn back (時計を) 巻き戻す pleasantly 心地よく expected to 〜するだろうと思う good 利益 majority 大多数。 大部分 take back 取り消す apparently どうやら~らしい close to ~近く be nice to 〜にやさしい junk food ジャンクフード concern for 〜への気遣い。 配慮 )に適切な語を入れなさい。 問1 ), (5) ( (1) (were ) (5) ( that ) 問2 下線部(2) は具体的にどのような能力ですか。 日本語で答えなさい。 ( 問3 「下線部(あ)~(う)の which のうち, 他と用法の異なるものを1つ選び, 記号で答えなさ い。 ( う ) 問4 下線部(3) の内容を具体的に説明した次の文の( )に適切な日本語を入れなさい。 回答は( 大部分は ( に結びつくものと予想していたが, だった。 問5 下線部(4), (6) を日本語に訳しなさい。 (4) (6)

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数学 高校生

1番最後の[1][2]から、というところですが、 なぜ(-1)ⁿではなく(-1)ⁿ+¹なんですか💦

例題 28 重要 に分けて和を求める 00000 一般項がαn=(-1)"+1n2 で与えられる数列{an} に対して,Sn=ak とする。 (1) a2k-1+a2k (k=1, 2, 3, ......) を ん を用いて表せ。 (2) Sn= (n= 1, 2, 3, ......) と表される。 k=1 次のように頭を2つずつ区切ってみると Sn=(12-2)+(32-4)+(52-62)+...... =b₁ =b₂ 指針 (2) 数列{an}の各項は符号が交互に変わるから,和は簡単に求められない。」 =b3 ****** 上のように数列{6} を定めると, bk=a2k-1+αk (kは自然数) である。 よってm を自然数とすると [1] n が偶数, すなわち n=2mのときはS2m2=(-1)として求め られる。 k=1 k=1 1 [2]nが奇数、すなわちn=2m-1のときは,Sam = Sim-1+α2m より S2m12m-a2mであるから, [1] の結果を利用して Szm-1 が求められる。 このように, nが偶数の場合と奇数の場合に分けて和を求める。 (1) 2-1+a2x=(-1)2k(2k-1)^+(-1)2k+1(2k)2 =(2k-1)-(2k)=1-4k [1]=2mmは自然数)のとき m m S2m=(a2k-1+a2k)=(1-4k) =m-4. m= =1であるから Sn -m(m+1)=-2m²-m =-2(2)-=-n(n+1) [2]=2-1(mは自然数) のとき 2m+1. azm=(-1)2 '(2m)'=-4m² であるから S2m-1=S2m-a2m=-2m²-m+4m²=2m²-m n+1 m=- であるから 2 S,=2(n+1)_n+1=1/2(n+1){(n+1)-1} = n(n+1) [1],[2] から Sn=(-1)+1 2 -n(n+1) (*) (-1) =1, (-1)=-1 ={(2k-1)+2k} ×{(2k-1)-2k} S2m= (a1+a2) +(as+αs) +...... +(a2m-1+a2m) Sm=-2m²-mに 2=1/27 を代入して,n m= の式に直す。 <S2m=S2m-1+a2m を利用する。 S2m-1=2m²-mをnの 式に直す。 451 (*) [1], [2] のS” の式は 符号が異なるだけだから, (*)のようにまとめるこ とができる。 一般項がαn=(-1)n(n+2) で与えられる数列{an} に対して, 初項から第n項ま での和 S を求めよ。 1 章 ③種々の数列

解決済み 回答数: 1