Grade

Type of questions

Mathematics Senior High

2)、実数解が存在するための条件に関する質問です。 (1)で出てきた不等式が満たされればxが実数解を持つ。そのために不等式をyの関数とみて、yの最大値が0以上となるときの条件が、(*)をみたすxの存在条件になるのは分かってるつもりなんですが(簡単に言うとyも変数であるからだ... Read More

54 第2章 複素数と方程式 標問 22 判別式 a b を実数の定数とするとき r'+y'+axy+b(x+y)+1=0 について考える. 以下の問いに答えよ. (*) α-2<0 より 求める条件は -462+4(a+2)≦0 すなわち J SE 55 MOORCONS ES 1% 0=8 +0+ (0) 62≧a+2 2次方程式 ax2+bx+c=0(a≠0) の解は x= -b±√b2-4ac 2a であり, a,b,cが実数のとき,D=62-4ac の符号により (2) 2<a<2 とする.(*)をみたす実数x, y が存在するための条件をα b (1) 実数y を固定したとき,についての2次方程式(*)が実数解をもつため の条件をα by を用いて表せ . 研究 (岐阜大) を用いて表せ. →精講 (1) について式を整理します . (*)は,実数係数の2次方程式ですか 解法のプロセス (1) 実数係数の2次方程式が実 数解をもつ ら 実数解をもつ (判別式) ≧ 0 が成り立ちます。 (2) (1)で実数が存在する条件をおさえてある ので、あとは実数y が存在する条件を求めます。 (1)で得た不等式を」についての2次関数のグラフ として考えるとよいでしょう. 条件 -2<a<2 はこのグラフが上に凸であることを示しています. <解答 (1)yは固定されている. (*)をæについて整理すると 2+(ay+b)x+y+ by + 1 = 0 ↓ (判別式) 0 (2) 2次関数f(y) のグラフが 上に凸であるとき f(y) ≧0 をみたす実数が 存在する ↓ f(y)=0 の (判別式) 0 判別式をDとおくと, (*)が実数解をもつための条件は, D≧0 である. D=(ay+b)2-4(y2 + by +1) より (a²-4)y°+26(a-2)y+62-4≧0 ......① (2) 2<a<2 のとき,不等式① をみたすyが存在するための a, b の条件を求 めればよい. f(y)=(a²-4)y2+2b(a-2)y +62-4 とおくと,-2<a<2であるから a-4<0 であり,f(y) のグラフは上に凸である. したがって,f(y)≧0 をみたす実数yが存在するための a,b の条件はf(y)=0の (判別式)≧0 である. b2(a-2)-(a2-4)(62-4)≥0 ..(a-2){62(a-2)-(a+2)(62-4)}0 ..(a-2){-462+4 (a+2)}≧0 D>0 ⇔ 異なる2つの実数解をもつ D=0 ⇔ 重解をもつ D<0 異なる2つの虚数解をもつ といった具合に解を判別することができる. a,b,c のいずれかが虚数のときは,判別式により, 重解であるか否かの 判別は 62-4ac = 0, 0 により可能であるが, 実数解をもつか否かの判別 はできない. 注意が必要である. 例えば, 虚数を係数にもつ2次方程式 x2-2ix-2=0 の判別式をDとおくと D MC =(-i)-(-2)=-1+2=1 (D≠0 より重解でないことが分かる) 判別式は正であるが, 解の公式より x=i±√1=i±1 であり,実数解をもたない.さらに, 方程式 2-(1+i)x+i = 0 である。 は 2-(1+i)x+i=(x-1)(x-i) と変形されるから x=1, i と 実数解と虚数解が共存する. 虚数を係数にもつ2次方程式については演習問題 30-130-2 も参照 せよ. 標問 109では3次方程式の判別式についても扱っている. + y 演習問題 A 22 整数とし, 2次方程式(k+7)'-2(k+4)x+2k=0 が異なる2つ (中京大) の実数解をもつとき,kの最小値および最大値を求めよ. 第2章

Waiting for Answers Answers: 0
English Senior High

教えて欲しいです。単元は動詞の語法です

1. When I realized I was wrong, I apologized ( Dhim my mistake 3 to him my mistake him for my mistake to him for my mistake 2. I graduated ( ) high school in 2015.m 1 from duo@for 3. We ( ) the problem of poverty. ①discussed 3 discussed of インター bist 4. Do you think I ( ) my elder sister? Dresemble resemble with (立正大) 4 of ③at de (酪農学園大) discussed about the discussed with して楽しめる b biabidea (東洋大) 3 resemble for b①am resembling 5. Kate () her baby boy on the bed after dinner. bid oa ed or blu ①laid lain give/tal 3lay 9131 (京都産業大) lie blow- em evig bnim LOV (広島修道大) ①raise ②rise wwo no alim to no 6. Please ( ) your hand if you want to ask a question. to baim w prey set up hard ratake up Sunda tegral 'nob 98819 7. Because of the bad weather, I decided ( ) out. ①not to go vud king/from home last night, to not going ③not going ④going not yud o (清泉女子大) guinisque beringsr 8. The repair shop failed ( ) my car. (東北芸術工科大) ①to fix 2 to affix ③fixed ④fix Ieva un baimer) Botong sandT 9. There was a big fire yesterday. Fortunately, everybody managed (). 011 (亜細亜大) Descape escaped Bevig 3 would escape aDob to escape 10. I closed my eyes and pretended ( ) asleep. o be Last wee toob edT 880 of Obe evig(玉川大) being 3 of being to be toy mailliW bus arrotiv 280 (to) during the exam.

Waiting for Answers Answers: 0
English Senior High

英語の長文です 文法表現があるところが知りたいです!

UNIT 5 Reading Passage 5 10 15 20 20 25 Listening There is a saying in France that states: "The government could fall, the Louvre¹ could be broken into, or aliens could land on Earth, but if any of these things happened during the Tour de France, no one would notice." The Tour de France is the most famous cycling race in the world. The which is held in July every year, consists of twenty one-day stages, plus several rest days. The course follows a clockwise route around France, and often neighboring countries, including Luxembourg, Belgium, and Italy. The winner is the rider who completes all twenty stages of the race in the shortest overall time. race, The Tour de France first started on July 1, 1903, when sixty cyclists left from in front of The Alarm Clock Café, just outside of Paris, and rode 467 kilometers to Lyon. The first race consisted of six legs, each of which was about 400 kilometers long. At that time, there were no rest days the winner was the rider who finished the race in the shortest total time. The winner of the first Tour de France, Maurice Garin, the most popular cyclist in France at that time, received 2,000 francs (about $350). It took him 94 hours and 33 minutes to ride all 2,428 kilometers of the race, three hours faster than the runner-up.² Over the weeks during which the race was run, the idea of the Tour de France slowly caught on with the people of France. The race has been held every year since that time, except during the years of World Wars I and II.³ The Tour de France has developed several special honors for which racers compete. The highest honor is the "yellow jersey." Henri Desgranges, the founder of the race, introduced the yellow jersey in 1919 to show the leading racer each day of the Tour de France. Each day, the officials who keep track of all of the riders' times compare each rider's total time up to that point. The racer with the lowest overall time wears the yellow jersey during the following day's race. Other honors include the "green jersey," which is given to the best sprinter, and the "polka dot jersey," a white jersey with red dots, for the best rider in the mountains along the route. Over the years of the race, the competitors have gained a reputation for good sportsmanship. For example, if a lead rider falls off his bike, it is common for the following riders to slow down to allow the fallen rider to catch up. Some watchers are surprised by this, but as German rider Jan Ullrich, who came in runner-up in 2002 after waiting for winner Lance Armstrong, says, "Of course I would wait. If I would have won this race by taking advantage of someone's bad luck, then the race was not worth winning." 1 the Louvre a famous museum in Paris 2 runner-up someone who comes second in a race or other competition 3 World Wars I and II 1914-1918 and 1939 - 1945 abent ages

Waiting for Answers Answers: 0
English Senior High

英語の長文です どこに文法表現があるか知りたいです! よろしくお願いします。

5 UNIT3 Reading Passage 10 15 20 20 25 30 Listening When important events are happening around the world, most people turn to traditional media sources, such as CNN and BBC,¹ for their news. However, during the invasion of Iraq by the United States and its allies in early 2003, a significant number of people followed the war from the point of view of an anonymous² Iraqi citizen who called himself "Salam Pax" (salam means "peace" in Arabic, and pax means "peace" in Latin). Salam Pax wrote a diary about everyday life in Baghdad during the war, and posted it on his web site. Pax's online diary was a kind of web site known as a "blog." Blogs, short for "web-logs," are online diaries usually kept by individuals, but sometimes they are written by companies and other groups of people. They are a rapidly growing type of web site on the Internet. There are estimated to be several hundred thousand blogs on the Internet, and with the popularity of other social media sites, the number of people writing online about their lives continues to grow. may find A blog differs from a traditional web site in several ways. Most importantly, it is updated much more regularly. Many blogs are updated every day, and some are updated several times a day. Also, most blogs use special software or web sites which are specifically aimed at bloggers, so you do not need to be a computer expert to create your own blog. This means that ordinary people who computers difficult to use can easily set up and start writing their own blog. In 2003, the Internet company AOL³ introduced their own blogging service, enabling its 35 million members to quickly and easily start blogging. There are many different kinds of blogs. The most popular type is an online diary of links, where the blog writer surfs the Internet and then posts links to sites or news articles that they find interesting, with a few comments about each one. Other types are personal diaries, where the writer talks about their life and feelings. Sometimes these blogs can be very personal. There is another kind of blogging, called "moblogging," short for "mobile blogging." Mobloggers use cell phones to take photo's, which are posted instantly to the Internet. When the content and images posted online involve news subjects, mobloggers become citizen journalists. In fact, the Korean web site OhMyNews was a well known source for articles from international citizen journalists. However, in 2010, OhMyNews stopped posting new articles. Instead, it is now a blog site where citizen journalists can choose what makes the headlines, or just share ideas about how regular people are changing the news world. Anyone who visits the web site of a big media company can clearly see how the idea of blogging has changed the reporting of news. Quite often, a list of reader comments follow news articles. It seems that the news is becoming less like a report or a lecture, and more like a conversation, where anyone can join in. CNN, BBC Cable News Network, British Broadcasting Corporation anonymous not named; unknown 3 AOL America Online

Waiting for Answers Answers: 0