1枚目のan≠0となる証明は理解できたのですが、 2枚目のa1=1>0、an+1=2√an>0より全ての自然数はnに対してan>0であるのはよくわかりません。また、「ーに対してan>0」ってどう言う意味なのでしょう？？

基本例題 119 an+1= ST によって定められる数列{an}の一般項を求めよ。 [類 早稲田大〕 基本116 2 an+1= 指針 漸化式 αn+1= an 4an-1 an のように,右辺の分子が α の項だけの場合の解法の手順は panta ① 漸化式の両辺の逆数をとると 答 CHART 漸化式 an+1= an+1= 1=b, とおくと bn+1=p+qbn an an 型の漸化式 bn+1=b+▲の形に帰着。 p.560 基本例題 116と同様にして一般項 bn が求められる。 また,逆数を考えるために, an=0(n≧1) であることを示しておく。 ところが α= panta したがって an ...... ① とする。 SORTIO 4an-1 ① において, an+1=0 とすると α = 0 であるから, an=0 とな るnがあると仮定すると an-1=an-2==q=0 an= 1 a₁=²/²/² ( (0) であるから,これは矛盾。 よって,すべての自然数nについて αn≠0 である。 ① の両辺の逆数をとると 1 an+1 an 両辺の逆数をとる panto 1 bn 9 -=-= an an+1 =4- bn+1=4-bn an bn+1-2=-(bn-2) 1 = b とおくと an これを変形すると また 1-2=5-2=3 b1-2=- a1 ゆえに,数列{bn-2} は初項 3,公比 -1 の等比数列で bn-2=3.(-1) すなわち bn=3・(-1)"'+2 1 3.(-1)"¹+2 19 00000 Egon an=05 an-1=0 これから an-2=0 以後これを繰り返す。 33d= 逆数をとるための十分条件。 1 an+1 THO Jia Il si ◄bn= 4an-1 an 特性方程式 α =4-α から α=2 an bn=0 という式の形から 565 3章 15 漸化式と数列 で , n). き き q 数 c)dx )に

この問題でthatが同格のthatと思っていたんですが、違うみたいでなぜ違うのか理由が知りたいです。教えて下さい。

4 The division of Germany between the Soviet Union and the West a was one feature of a bi-polar world order that capitalist and b communist states raced to develop nuclear weapons. NO ERROR

英検２級のライティングです。 添削をお願いしたいです😿

It is often said that restaurants, and supermarkets should try to reduce the amount of food that they throw away. Do you agree this opinion? I agree the opinion that restaurants and supermarkets should try to reduce the amount of food that they thinw I have two reasons to support this opinion. Firstly, It is bad for the enviroment two throw away the food. To throw away the food lead to global warming Secondly, reducing food waste is one of critical factors Developing contries have a lack of safe food If wealthy countries reduce the amount of food that they throw away, people in developing countries will happy. for these reasons f mentioned above, I believe that we should reduce the amount of food that the restraunts and supermaket's throw away,

空間図形　中3 ⑵の求め方を教えて欲しいです

3²=X² 2 {TO + 2² = x² 1044 (59 cm cm 2cm = x². x = √TA (2) (3) cm cm 円の中心点Qは母線の中点 (2) 四角形 ABPCは正方形, DQ=QE D B (3) n ■すい, (2)は三角柱, (3) は円柱の展開図である。 この展開図を組み立ててできる立体について, 6cm- 4cm P cm C E (4) STA cm (2) √√59 cm (3) 7 cm (4) √√14 cm (5) AG=9cm, PC= m (2) 7 cm (3) √√31 cm cm | AG= 4√65 cm 9 (5 6cm cm (3) BP=PQ=QD B P 3cm

所々の単語はくっつくのですが文になると難しいです。教えてください

Try it out! am agged wi 1 ( 1. Many people say brown rice (healthier /is/ rice / much/white/than ). 2. To stay fit, sleeping (as/is/ doing / meaningful / as / exercise ). 3. It is said that the more you chew, (you/ the / eat / less). 4. Jogging is (forms / the /of/ most popular/ one) of exercise. の中の語を並べ替えて、英文を完成させましょう。

この問題の(4)なのですが、 I will try anything faster than any other student in my class. どんなことも他の人(クラスメート)よりも早く挑戦する と解答したのですが、あっていますか？ 添削お願いします。

19 ハルナ(Haruna) がヒューズ先生 (Mr. Hughes) と話をしています。この対話文を読んで、 [1]~[(3) に入る最も適当なものをそれぞれあとのア~エのうちから一つずつ選び、その 符号を書きなさい。 また、対話文の内容に合うように、 (4) に入る言葉を英語で書きなさい。 ただし、語の数 は10語程度(.?! などの符号は語数に含まない。) とすること｡ Haruna Mr. Hughes, do you have time ? Mr. Hughes Of course. Do you have any questions? Haruna:Yes, at the end of the class, you said, "Be the first penguin." (1) Mr. Hughes: All right. You know penguins, right? Penguins are birds that cannot fly but car swim in the sea. Haruna Yes, of course. I have seen them in an aquarium. Mr. Hughes : Some people say that there is no leader in the world of penguins but that is not true. When they catch food or run away to a safe place, one penguin moves first, and then the rest of them (2) Haruna Mr. Hughes: Wow, that's very interesting. For example, (3) | to jump into the sea to catch food because there is sometimes danger in the sea. But when one brave penguin jumps into the sea, all 0000/r

わからないので答えを教えてもらいたいです。

英語 Amy: Hey Jake, I was thinking about online shopping this weekend. Do you shop online often? Jake: Yeah, I do it quite a bit. It's so ( house and you can ( ) almost anything online. That's true. I love the convenience, too, especially with a busy schedule. But I've heard there are some downsides to it. What do you think? Well, one obvious downside is not being able to ( ) or try the product before buying. Sometimes, what you see on the website isn't exactly what you get. Amy: Yeah, that's a good point. I've had a couple of instances where the color or size was ) from what I expected. ( Another thing is the shipping time. Even with express shipping, you might have to ( ) a few days for your stuff to arrive. It's not great if you need Amy: Jake: Jake: Amy: Amy: Jake: Jake: Jake: something urgently. True, waiting can be frustrating. But what about the ( that sometimes the prices are higher online. It depends. I've found some great deals online, especially during sales. But you're right; in some cases, the prices can be a bit inflated, and you might end up paying more than if you bought it in-store. Amy: And returns can be a hassle, too. I had to return a shirt once, and the process took forever. It's not as easy as just going to a store and returning it on the spot. Yeah, returns can be a pain. Also, there's the whole security issue. You must be careful about where you're buying from to avoid scams or stealing your ( ). Amy: Oh, definitely. I always make sure the website is secure before entering any payment details. 日本語 L ), you know? No need to leave the On the bright side, online ( ) can be super helpful. I always check them before making a purchase. It gives you an idea of the product's quality and whether it's worth the money. Amy: That's a good point. I do the same. It's like having the opinions of a bunch of friends who've already ( ) the product. Jake: Exactly. So, while there are some drawbacks, I think the ( ) of online shopping, like the convenience and variety, outweigh the ( ) for me. Yeah, I agree. It's all about finding a balance and being cautious about where and what you're buying. )? I've heard

(1)Let's go out to eat something for dinner. (2)Could you help me look for my room key? と解答したのですがあっていますか？ 添削お願いします。

6 次の①~④は、大学生のタクヤ (Takuya) が、 友人のロドリゴ (Rodrigo) とアメリカに旅行し た時の出来事を描いたイラストです。 ②⑨の場面で、タクヤは何と言ったと思いますか。 ① ~④の話の流れを踏まえ, (1) [2] に入る言葉を英語で書きなさい。 ただし、語の数はそ れぞれ10語程度(..?! などの符号は語数に含まない。) とすること。 3 HOTEL I'm so hungry. (1) Where is the room key ? Takuya Rodrigo That's a good idea! Excuse me! | An hour later (2)

4番の問題はどうしてto beをつけなければいけないのですか？ 教えてください🙇‍♀️

(p. 279) EXERCISES 1.次の()内の動詞を(必要なら助動詞を加えて) 適当な形に変えなさい 1) Kate (be) angry if she had learned the truth. would have been 2) If I (be) in her place, I'd allow John to join the club. were If you had listened to me, you (not make) that mistake. would have not made If I (be) born again, I would like to be an artist. were to be . 11 I not it wou 助動詞 Tint

（1）（3）〜（6）教えてください

2 次の英文を読んで,あとの各問いに答えなさい。 Nancy and Saori are fifteen years old. Nancy came to Japan from New York last week. They are *neighbors. (1) Yesterday Saori invited Nancy to a welcome party. When Nancy came to Saori's home, Saori's mother said, We are going to have a party for you.” “Hi, Nancy. Today I'm going to 5 make sushi,” said Saori's father. Then Saori asked, “Do you like sushi?” “Yes, I like it very much, " Nancy answered. Then Saori's father went to the kitchen with Saori's mother to make sushi. Nancy and Saori went to the *living room and enjoyed ② (talk). Nancy asked Saori, “I have never made sushi *myself. “No, it's easy. Let's try next time,” said Saori. (3) An hour later, Saori's mother (to / to / told / come / the table / Nancy and Saori). When they *were ready to eat, Saori said something. “What did you say?" Nancy asked. “I said, Itadakimasu. We say it before eating.” Nancy said, “What does it mean?” Saori thought for a while and said, “*Maybe it means 'I will eat it.' It's an *expression to use before eating.” “Is there an expression to use (⑤) eating?” “Yes, Nancy. It's 'Gochisosama. It means ‘It was good food,' I think.” “Oh, I see. I've just learned two new Japanese expressions." Then Nancy said, “Itadakimasu,” and started 15⑥(eat). 10 〔注〕 neighbor 隣人 living room 居間 myself 私自身で ~ be ready to 〜 〜する準備ができている maybe たぶん expression 表現、語句 ① に適する文をア~エから選び, 記号で答えなさい。 (1) ア You are welcome. イ Nice to meet you. ウ Excuse me. (2) ②, ⑥の()内の動詞を,適する形 (1語) になおして書きなさい。 ② talking ⑥ eating (6) (3) 話の流れに合うように, ③に適する疑問文を書きなさい。 I I'm sorry. ( ) 8 (4) 下線部④が意味の通る正しい英文になるように,( )内の語句を並べかえなさい。 An hour later, Saori's mother (5) (⑤) に a で始まる適する1語を書きなさい。 (6) 本文の内容と合うように、次の問いに3語の英文で答えなさい。 Was this the first time for Nancy to eat sushi? SOMNB ******* et aid?