判別式dが0以上なのはどうしてですか？　＝を入れると解が一個なので問題文の「二つの解が」を満たしてないと思う

78 基本例題 50 2次方程式の解の存在範囲 (2) ON xについての2次方程式x2(a-1)x+a+6=0 が次のような解をもつ CHARTO SOLUTION 解答 うな実数aの値の範囲をそれぞれ求めよ。と (1) 2つの解がともに2以上である。 (s) (2) 1つの解は2より大きく,他の解は2より小さい。 MOIT ①から 実数解 α, β と実数kの大小 a-k, β-k の符号から考える (1) 2以上とは2を含むから, 等号が入ることに注意する。 a≥2, B≥2 ⇒ (a−2)+(B-2)≥0, (a-2)(B-2) ≥0) (2) a<2<ß #tel B<2<a ⇒ (a-2)(B-2)<0 O x2-(a-1)x+a+6=0 の2つの解をα, β とし, 判別式をD とすると D={-(a-1)}2-4(a+6)=a²-6a-23 解と係数の関係により a+B=a-1, aß=a+6 (1) α≧2,β≧2 であるための条件は,次の ①, ②, ③ が同時 に成り立つことである。 D≧0. (a-2)+(B-2) ≥0 (a-2)(B-2)≥0 a²-6a-23≥0 *****. a≦3-4√2,3+4√2≦a‥. ゆえに a+B-4≥0 a≥5 3 ② から よって ⑤ ③から aß-2(α+β)+4≧0 ゆえに a+6−2(a-1)+4≧ 0 (a-2)(B-2)<0 よって a+6-2(g-1) CHOOS83 (a-1)-4≥0 ④,⑤,⑥の共通範囲を求めて 3+4√2 ≤a ≤12 (2) <2<Bまたはβ<2<αであるための条件は よって a≦12 p.71 基本事項 基本 6. inf. 2次関数 f(x)=x2-(a-1)x+a のグラフを利用すると (1) D≥0, ( 軸の位置) ≧ 2, ƒ(2) ≥0 f(2) x= a 2 (2) f(2)<0 (p.715 [補足] 参照)

この問題を何度やっても答えがうまく出ません…どこから間違っているのか教えてください💦

基本例題 32 1次不等式と文章題 Aの箱の重さは 95g, Bの箱の重さは100gである。 1個12gの球が20個あ り,これらをAとBに分けて入れたところ, Aの箱の方が重かった。 そこで Aの箱からBの箱に球を1個移したところ,今度はBの箱の方が重くなった。 最初, Aの箱には何個の球を入れたか。 基本30 CHART & SOLUTION 文章題の解法 ① 変数を適当に定め、 関係式を作って解く ② 解が問題の条件に適するかどうかを吟味 最初,Aの箱の球をx個としたときのAとBの重さを比較した関係式を作る。 次に,Aの箱の球を1個減らし、Bの箱の球を1個増やしたときの重さを比較した関係式を 作る。こうしてできる2つの不等式を連立させて解けばよい。 なお, xは自然数であることに注意する。 答 (1) 2 を満た 最初, Aの箱にx個の球を入れたとすると A,Bの重さを比較してながら 95+12x>100+12(20-x) 95+12(x-1)<100+12(21-x) 整理して 24x>245 よって Aの箱から1個減らし, Bの箱に1個増やしたとき A,Bの重さを比較して 整理して 24x<269 よって ①と②の共通範囲を求めて 245 24 x> 245 24 269 24 x <- <x<- 269 24 のを実Bは (20-x) 個 xは自然数であるから x=11 したがって, 最初Aの箱に入れた球は11個である。 .. 1 ←Aの方が重い ◆Aは (x-1) 個, Bは (20-x+1) 個 ←Bの方が重い。 245 24 ◆解の吟味。 ≒10.2, 269 24 ≒11.2 1章 4 1次不等式

自分なりに一番を解いたのですが、なぜかうまく行きません…どこから違うか教えてください💦

因数分解 (対称式・交代式) 基本例題 16 次の式を因数分解せよ。 a(b+c)²+b(c+a)²+c(a+b)²-4abc (2) x(y2-22)+y(z2-x2)+2(x2-12) CHART & SOLUTION 対称式・交代式の因数分解 1つの文字について降べきの順に整理する どの文字についても次数は同じ。 どれか1つの文字に着目して整理する。 (1) a²+a+ (2) x2+x+ 解答 (1) a(b+c)²+b(c+a)²+c(a+b)²-4abc = a(b+c)²+b(c²+2ca+a²)+c(a²+2ab+b²)-4abc =(b+c)^²+{(b+c)2+2bc+2bc-4bc}a+.bc'+62c = (b + c)²(b + c)²a+bc(b+c)_ =(b+c){a²+(b+c)a+bc}」 =(b+c)(a+b)(a+c) =(a+b)(b+c)(c+a)j (2) x(y2-22)+y(22-x²)+2(x2-y2) =(-y+z)x2+(y²-22)x+yz²-y2z =-(y-z)x2+(y+z)(y-z)x-yz(y-z) =-(y-z) {x-(y+z)x+yz} =-(y-z) (x-y)(x-2) =(x-y) (y-z) (z-x) [(2) 鹿児島経大] ③ 基本 14,15 αについて降べきの順に整 理する。 DETE a²+a+ ← (b+c) が共通因数。 これを答えとしてもよい。 輪環の順に整理。 xについて降べきの順に整 理する。 ●x2+x+ ←(y-z) が共通因数。 これを答えとしてもよい。 輪環の順に整理。 1章 2 因数分解

(8)についてです。答えは以下の通りなのですが、最後についているaqとは何を意味するのですか？？

☆お気に入り登録 例題4 例題 ④ ボルタ電池・ダニエル電池 右図の電池 Ⅰ・ⅡIについて次の各問いに答えよ。 (1) 電池Ⅰで負極は亜鉛板、銅板のどちらか。 そ の理由も答えよ。 (2) 電池Iで亜鉛板上の反応を,電子eを用い た反応式で表せ。 (3) 電池ⅡIで素焼き板の果たしている役割を説明 せよ。 電池Ⅰ (4) しばらく放電を続けると, 反応がより早く停止するのはどちらか。 その理由も答えよ。 (5) 電池 Ⅰ・ⅡIで銅板上での反応をそれぞれを用いて表し, その違いを説明せよ。 (6) 電池ⅡIで銅板の代わりに銀板を用いるとき, 起電力はどうなるか。 理由も答えよ。 (7) 電池ⅡIの負極活物質と正極活物質をそれぞれ化学式で答えよ。 (8) 電池ⅡIを長持ちさせるためには,どちらの水溶液の濃度を高くさせればよいか, 化学式で 答えよ。 Zn H2SO4aq Cu Zn ZnSO4 aq CuSO4 aq -素焼き板 電池Ⅱ

3行目の不等式のところが分かりません。 解説お願いします!!

文字はすべて実数とする。対偶を考えて,次の命題を証明せよ。 (1)x+y=2 ならば 「x≧1 または y≧1」 (2) '+626 ならば 「la +6/>1または |a-b>3」 解答 (1) 与えられた命題の対偶は CHART & SOLUTION 対偶の利用 命題の真偽とその対偶の真偽は一致することを利用 (1) x+y=2 を満たすx,yの組(x,y) は無数にあるから、 直接証明することは困難であ る。 そこで, 対偶が真であることを証明し,もとの命題も真である, と証明する。 条件 「xlまたは y≦1」の否定は 「x>1かつy>1」 (2) 対偶が真であることの証明には、次のことを利用するとよい。 A≧0, B≧0のとき A≦B ならば A'≦B (p.118 INFORMATION 参照。) 「x>1かつy>1」 ならば x+y=2 00000 これを証明する。 x> 1, v>1 から x+y > 1+1 すなわち x+y >2 よって, x+y=2であるから、 対隅は真である。 したがってもとの命題も真である。 p.76 基本事項 6 pg の対偶は q=p x>a,y>bならば x+y>a+b (p.54 不等式の性質〉

和訳お願いします。

次の英文を読んで, 設問に答えなさい。 [5] The headline grabs your attention: "The ancient tool used in Japan to boost memory." You've been The Japanese art of racking up clicks online more forgetful recently, and maybe this mysterious instrument from the other side of the world, no less! could help out? You click the link, and hit play on the video, awaiting this information that's bound to change your life. The answer? A soroban (abacus). Hmm, () それは私がどこに鍵を置いたか覚えておく助けになりそうには ないですよね? This BBC creation is part of a series called "Japan 2020," a set of Japan-centric content looking at various inoffensive topics, from the history of Hiroshima-style okonomiyaki pancakes to pearl divers. The abacus entry, along with a video titled "Japan's ancient philosophy that helps us accept our flaws," about kintsugi (a technique that involves repairing ceramics with gold-or silver-dusted lacquer), cross over into a popular style of exploring the country: Welcome to the Japan that can fix you. For the bulk of the internet's existence, Western online focus toward the nation has been of the "weird Japan" variety, which zeroes in rare happenings and micro "trends," but presents them as part of everyday life, usually just to entertain. This sometimes veers into "get a load of this country" posturing to get more views online. It's not exclusive to the web traditional media indulges, too but it proliferates online. Bagel heads, used underwear vending machines, rent-a-family services - it's a tired form of reporting that has been heavily criticized in recent times, though that doesn't stop articles and YouTube videos from diving into "weird Japan." These days, wacky topics have given way to celebrations of the seemingly boring. This started with the global popularity of Marie Kondo's KonMari Method of organizing in the early 2010s, which inspired books and TV shows. It's online where content attempts to fill a never-ending pit - where breakdowns of, advice and opinions about Kondo emerged the most. Then came other Japanese ways to change your life. CNBC contributor Sarah Harvey tried kakeibo, described in the headline as "the Japanese art of saving money." This "art" is actually just writing things down in a notebook. Ikigai is a popular go-to, with articles and videos popping up all the time explaining the mysterious concept of ... having a purpose in life. This isn't a totally new development in history, as Japanese concepts such as wa and wabi sabi have long earned attention from places like the United States, sometimes from a place of pure curiosity and sometimes as pre-internet "life hacks" aimed making one's existence a little better. (B) The web just made these inescapable. There's certainly an element of exoticization in Western writers treating hum-drum activities secrets from Asia. There are also plenty of Japanese people helping to spread these ideas, albeit mostly in the form of books like Ken Mogi's "The Little Book of Ikigai." It can result in dissonance. Naoko Takei Moore promotes the use of donabe, a type of cooking pot, and was interviewed by The New York Times for a small feature this past March about the tool. Non- Japanese Twitter users, in a sign of growing negative reactions to the "X, the Japanese art of Y" presentations, attacked the piece... or at least the headline, as it seemed few dove the actual content of the article (shocking!), which is a quick and pleasant profile of Takei Moore, a woman celebrating her country's culinary culture. Still, despite the criticism by online readers, the piece says way more about what English-language readers want in their own lives than anything about modern Japan. That's common in all of this content, and points to a greater desire for change, whether via a new cooking tool or a "Japanese technique to overcome laziness." The Japan part is just flashy branding, going to a country that 84% of Americans view positively find attention-grabbing ideas for a never-ending stream of online content. And what do readers want? Self-help. Wherever they can get it. Telling them to slow down and look inside isn't nearly as catchy as offering them magical solutions from ancient Japan.

(2)で、なぜbを-bに置き換える必要があるのですか？

例題 次の不等式を証明せよ。 4-6 slä (2) lãi lời là tôi ả Hỏi CHARTO SOLUTION 不等式の証明 A≧0, B≧0のとき A≦BA'B' ・・・･･・ (1) 内積の定義を利用するか, または成分を用いて証明する。 成分を用いて証明 するときは, labs (ab) 2 を示す。 (2) まず、右側の不等式 la +6|≦|a|+|6| を証明する。 途中, (1) の結果が利用 できる部分がある。左側の不等式 |a|-||≦a +6|は、先に示した右側の不 等式を利用して示すとよい。 ①のとき, ことのなす角を0とすると a = |a||5|cose, -1≦cos0≦1 ゆえに |･|=|||||cos ||||| が成り立つ。 =(a,b)=(c, d) とすると (a|| b)²³-√ã• b³²=(a²+b²)(c²+d²)−(ac+bd)² more [syds to または=0のとき, 76=0,1261=0であるから (1) 条件「=」または 0」の否定は ||18|=|||| 「ad かつ前」 ||||) PRACTI ITUIO = a2d2+b22-2acbd=(ad-bc)≧0 |≧||||≧0であるから |à·b|≤|a||b| (2) (1) ³5 (lã|+| 6 |) ² −|ã+6³² S ゆえに(161) 2 lãi Hỏi 20, là tỏ 20375 ① においてをa+, を一とすると la+b|≤|a+b... (1 là la +6-6①+6+1-6 <[-+ ⑩0=1-5 よって ||≦la +6+161 0212a-16|≤|a+b......2 0.0+5 |ä1-16 |≤|ã+b|≤|a|+|b| p.352 基本事項] =là³²+2|a||6|+|6³²−(|a³²+2a •6+16³}____=(a+b)·(ä+b) =2(|à ||b|—à·b) ≥0 ◆ (1) から |cos6|≦1 等号が成り立つのは, a = 0 または = 0 また a // のとき。 365 inf. la bab -lä||b|≤à·b≤|à||b|| と表すこともできる。 <la+b1² を証明せよ。 a.b≤la.bl≤labl ■16=16 をベクトルの三角不等式ということがある。 S 1章

4の解き方がわかりません。 例えば(a)で、続く文であくびを謝っていることも全て把握した上で、挨拶なのでpolitelyかと考えたのですが、なぜ誤りなのか教えていただきたいです。

13 Lucy is a British schoolgirl who lives in Oxford. She is talking to her father, Fred, in the kitchen of their home. Read the conversation below and answer the following questions. Lucy: (a) Good morning, Dad. Oh, sorry for yawning. What are you doing with that microwave oven? It looks heavy. Do you need a hand with moving it? Fred: I think I'll be OK, Lucy. I'm just going to put it in the car and take it to the city dump. Lucy: Couldn't you send it away to be repaired? Fred: It's ten years old and well out of warranty now, so I very much doubt that the manufacturer would do it. They probably don't even carry the spare parts anymore. Lucy: That's a shame. Oh, I know what! Why not take it to the Repair Café near my school? Fred: What's that? I've never heard of it. Lucy: It's brilliant! We visited it as part of our environmental science course recently. It's a meeting place where people can get together to mend broken items cooperatively. And have a chat and a cup of coffee! Fred: I'm all ears. Tell me more. Lucy: Well, the first Repair Café was started by a Dutch woman called Martine Postma in Amsterdam in 2009. (1) 彼女は,使い捨て文化で環境が破壊されて, ゴミの量が地球規模で増えることを心配してたん . She wanted to find a local solution to this global problem. Fred: That's what they call "thinking globally, acting locally," isn't it? Lucy: Exactly. She also wanted to address the decline in community spirit amongst urban dwellers and do something about people's loss of practical skills and ingenuity. Fred: And the idea (2) caught on? Lucy: Very much so. The concept has grown into a global movement. The one in Oxford started about four years ago. Fred: Impressive! What kind of things do they repair? Lucy: Oh, all sorts. Electrical appliances, clothes, furniture, crockery, bicycles, and even toys. Fred: How successful are they at repairing things? Lucy: Well, of course, they cannot guarantee to fix every item brought to them, but they have a fairly good success rate. One study found that on average 60 to 70 percent of items were repaired. The rate is higher for some items such as bicycles and clothes but lower for things like laptop computers. Fred: I can understand that. Just between you and me, I think some electronics manufacturers deliberately make products in such a way that you cannot disassemble them and repair them unless you have specialized tools and equipment. Lucy: Yes, and that's where Repair Cafés can help. But these cafés are not just about repairing things for people. They are places where we can meet others, share ideas, and be inspired. The volunteer repairers are very keen to involve the visitors in thinking about the repair and actually carrying out the repair themselves. They also encourage people to think about living together in more sustainable communities. Fred: I suppose you could say they are about repairing our minds, not just our things. Lucy: Quite so, although often the two are very closely related. Many people attach (3)sentimental value to old things that might, for example, be part of their family history. Fred: I see what you mean. It almost sounds too good to be true. (a)Is there a catch? For example, how much does it cost? Lucy: Advice and help from the repairers is free, but people who use the café are invited to make a donation. That money is used to cover the costs involved in running the café. If specific spare parts are needed, the repairers will advise you on how to obtain them. Fred: Well, that's marvelous! (e)Then I'll take this old microwave there. Are they open today? Lucy: Yes, and I'll come with you. I've got a pair of jeans that are badly in need of some attention. QUESTIONS 1. Translate the underlined part after (1) into English. 2. What does the underlined phrase after (2) mean? Select the most appropriate expression from the list below. (A) became popular (B) hit a dead end (C) occurred to you (D) played a significant role (E) worked in practice 3. The underlined phrase after (3) means the value of an object which is derived from personal or emotional association rather than its material worth. Give ONE object that has "sentimental value" for you and explain why it has such value. Your answer should be between 15 and 20 English words in length. (Indicate the number of words you have written at the end of your answer.)

わからないので教えてください

本文を読んで,英問英答を解こう。 7. What is Riku's dream? ( 7 words) ① 陸の夢はなんですか? Dream is to inventatime machine 8. What were inventors in the past interested in centuries ago ? ( 7 words) ここで何世紀も前に興味を持っていた過去の発明者は何ですか。 9. How did inventors like Leonardo da Vinci learn some of the secrets of flight? レオナルド・ダ・ヴィンチのような発明家は、ひこうのひみつをどのように 学んだのですか。 ( 9 words)

この1の時に成り立つということは間違ってないですか? もし問題で青線のとこが5ならば 1の時のX，Yを5倍するということですか?

1次不定方程式→ 一般解に文字を使った一般的な高 (134) 7x - 2y = 0 x S_ASB₁ X = 2k, y=1K (R₁2 特殊解 X=2₁ 9=7 解が無数に存在する!! 1573 ◎不定式の性質 A x + b y f 1 ax+by=1は選択解をもつ = 62 = 61x² P. 424 J 1²7966= 67.7 x1 +299 1677 = 299 × 2 + 69 299 = 69 x 4 +23 69 = (23) x 3 to 234 13 2077 = 1829 x1 +248 (82) = 248 x 7 +93 242 = 93x2 + 62 +31 93 = 62x1 x2 +0 77= 24 X211 291883 「無数ある!! 475x14 (132²107 具体的か の2つある!! No Date aとbが互いに素であるとき、 J 31 (2) 884=353×2+238 323 = 228 x 1 95 f 228 = 95 +2 +38 95 = 38x2 + 19 38=10x2 +o (9.