長方形で囲んでいるところなんですけど、どうして等比数列ですか？bn+1=2(bn-1)だったらわかるんですけど、左側に謎にマイナス一がついててよくわかりません。お願いします。

498 105tの1次式) 型の漸化式 次の条件によって定められる数(a)の一般項を求めよ。 -3, -20.-n CHART VOLUTION 漸化式 past (n の1次式) (1) ①1 階差数列の利用・・・・・・[2] ② +(n+1)=pla-f (n)) と変形 ・・・・・・ また ①から 更に 2の変形については右ページのズームUP を参照。 下の解答は山の方針による解法で、別解は②の方針による解法である。 +2=2x+1- (n+1), an+1=2an-n 辺々引いて bn=ants-an とおくと an+2ax+1=2(an+1−αn)-1 bx+1=2b-1 b₁-a₂-a₁=(2-3-1)-3=2 b-1-2(bn-1) 'b1-1=1 ゆえに,数列{bm-1} は初項1,公比2の等比数列となり bn-1=1.2"-1 b=2-¹+1 すなわち よって, n≧2のとき カー1 5 (21+1)=3+2"-1+(n-1) 2-1 k=1 =2"-1+n+1 α=3であるから, この式はn=1のときにも成り立つ。 したがって an=2"-1+n+1 別解 an+1=2an-n を変形すると an+1- (n+2)=2{an-(n+1)} jan+1=2an an+1 - an= +(n-1) から an+1を an=2n-1. 1-S α=2a-1 を a=1 また a₁-(1+1)=3-2=1 ゆえに, 数列{an- (n+1)} は, 初項1,公比2の等比数列と なり an-(n+1)=1.2-1 したがって α=2"-1+n+1 azza-n inf. bn=27-1 た後は 求めて <-n=12 20+1+ この変 参照。

面積を求める問題ですが、途中の変換式がよく分からないので、細かく教えて頂きたいです🙇🏻‍♀️

(配点50点) 座標平面において, æ軸上に3点(0,0),(0,0),(3,0)(0<a<β) があり, 曲線 C:y=x²+ax2+bx がx軸とこの3点で交わっているものとする. ただし, a b は実数である. このとき,以下の問いに答 えよ. (1) 曲線Cとx軸で囲まれた2つの部分の面積の和をSとする. Sa と βの式で表せ. (2)βの値を固定して,0<a<βの範囲でαを動かすとき, Sを最小とするαをβの式で表せ.

このハイフンで挟まれてるところってどうして、 〜からである　という訳になるのですか？？

接続詞 1⑩0 That might seem fair enough farmers must grow crops (so that people can S V S' C S OV 0 - eat), (after all) - but a huge amount of that precious water > is V' S wasted (on such foolish acts as I irrigating pastureland for dairy V & aceitio cattle>】》); it is an astonishing fact 【that [watering grass for pasture 》] SV (notsw a'otste edit to C 接続詞 S' swallows more water (every year) (than the cities of Los Angeles and V' O' 625 1928 San Francisco > < combined >) 1. 母の目を向け始めてさえいるのだ。 かんがい それは十分に正当なことに思えるかもしれない (結局) (人々が食べていけるように), 農 業経営者は作物を育てなければならないからである―しかし,〈その貴重な水の> かなりの 量は, 【く乳牛のための〉 牧草地 を灌漑する】 といったような》 愚かな行為のために) 浪費されているのである。【[《牧草のための》草に水をやるということ]が,(毎年)(《ロ サンゼルスとサンフランシスコの》<2つの〉都市よりも) 多くの水を消費するというこ とは驚くべき1つの事実なのである。 TAGRAPH

答えがないので教えて頂きたいです🙏🏻💧

第3回 078 079 080 ① 空所に入れるのに最も適当な語句を,下の①~ ④ から一つずつ選びなさい。 We will be arriving at Chubu International Airport ( ) 10 minutes. . 2 during by 3 for 4 in 076 077 071 072 073 074 075 Level 1 - PART C = The population of this city increased ( 1 of 2 at 3 by She was ill in bed. That's ( 1 because 2 why "You are going to take next week off, aren't you?" "Yes. ( ) my absence, I would like you to take over from me." 1 On 2 For 3 While 4 During ) three percer last year. 4 in He behaved as ( though ) she didn't come to the party. 3 what 4 when A book is not always good just ( 1 because 2 when When I got to the checkout counter, I realized that I didn't have enough money, so I kept ( ) I really needed and left the rest. 1 that 2 this 3 what ( ) you were not at the meeting, we made the decision without you. 1 Unless 2 Since 3 If ) nothing had happened. 2 soon as 3 for For The number of students in my reading class ( 1 is (2) are have (名古屋外語大) (南山大) (大) 4 which (センター試験) ) it is written by a famous writer. 3 while 4 as (4) to (高岡法大) ( ) her kind advice, he succeeded in passing the examination. 1 In case of Far from On earth 4 Thanks to (京都学園大) (東海大) (創価大) (中央大) ) limited to twenty-five. 4 has (専修大)

どれかひとつでも分かる人お願いします

【9】 次の1~4の文中, 下線の部分の意味を表す語を下記のa~fの中より選 びその記号を書きなさい。 1. As soon as I get through this homework, I will join you. 2. The American football game was called off owing to the heavy rain. 3. Kyoto is one of the best locations for making movies. 4. I waited half an hour for my friend, but she didn't appear. a. cancel b. turn up c. get by d. place e. finish f. answer 1 (15 2 3 4 (日本バプテスト看)

教えてください

ADORA TROY 8 367 dislyse 【11】 内容が同じになるよう下線の部分にそれぞれ三語ずつ英語を入れなさい。 (1) Five years have passed since our dog died. 1st ezeni yediom Our dog for five years. (2) No one could tell the time when he would arrive. bind de anw No one could tell the time boud.asw (3) "Don't make a noise, boys," he said.oris ow fai Tiss240 He told the boys a noise. (4) It seems she had a good rest. si ob She seems (5) You don't have to do it at once. do it at once. It is Juela d ob of 3sd a good rest. word Jan bibl

348 問 誤りを正せ なぜ、1がまちがってるのか また、どう直せばいいのか わかる方いらっしゃったら解説お願いします🙇‍♂️

348 ① She has ②hardly started ③reading the passage aloud 4④ when she coughed. 〈立命館大〉 ① 訳彼女はその一節を声に出して読 み始めたとたん, せきをした。

347 問 共通してはいる最も適当な語 なぜ4になるのか解説お願いします🙇‍♂️

347 (a) He have missed his train. (b) Business has been thriving in the past year. Long it continue to do so! 1 should ② shall ③ might ④ may 〈上智大〉 ④ 訳 (a) 彼は電車に乗り遅れたのか もしれない。 (b) 過去1年、事業はう まくいっている。 この状態が長く続 きますように!

教えてください

【9】 各組のa,bの文が,同じ意味になるように [ ]内に適語を入れな さい。 1. a. Study harder, or you will not pass the exam. b. [ ] you study harder, you will pass the exam. 2. a. I could not go out yesterday because I was ill. b. Illness kept me [] going out yesterday. 3. a. On arriving at the station, I telephoned her. b. As [] as I arrived at the station, I telephoned her. 4. a. Children were surrounding her when she was singing. b. She was singing [] by children. 5. a. He said to me, "Do you want to buy a car?" b. He asked me [ ] I wanted to buy a car.

このtoは全て副詞的用法だと思ったのですが合っていますか？

10 The American weekend officially begins on Friday evening, but already by Friday morning there are signs that the weekend is just around the corner. You see fewer cars on the highways, and buses and subways are less crowded with people, too. This is because 5 some people take a day off on Friday to have a three-day weekend. 2 Things are also different at work. People don't wear the same clothes as they wear on weekdays; they dress themselves more casually. For instance, managers in the office may put on casual sports clothes instead of coats and ties. Some people put on blue jeans. 10 3 This trend toward "easy Fridays" is popular with employees who normally wear uniforms to work. In Los Angeles, for example, bus drivers are usually dressed in military-style jackets, hats and trousers. Recently, however, they have received permission to wear polo shirts and baseball caps on Fridays. 154 Transportation officials believe that this new Friday *dress code is good for the drivers' *morale. And they are also sure that the just as long as the buses run on time. 17 passengers won't mind