学年

質問の種類

数学 高校生

(2)なんですが、どうしてγが0から1の範囲にあると分かるのか教えて頂きたいです!

5 解で (1)実数係数の方程式が虚数 α を解にもつ 考え方 両 あることを利用する。 つけ,できるだけ未知数の少ない式を立てることは大切である。 (x++)+("ィ++ (S a月 Process よ 解答 3+V7i を解にもつ実数係数の方程式は, (1)複素数a= 共役な複素数aも解 3-V7iも解にもつから,これらを2解とする2次方程 2 Q= 報O (0+) 0%3Db+x+d+ 天野さ 式は 3-V7i)。 3+/7i )-3-7) = 0 D x一 2 したが : -3x+4=0 -2a (2)(1)より, x+ax'+bx+cはx-3x+4を因数にもつ から,与えられた3次方程式の実数解をyとおくと x°+ ax°+ bx+c==(x-y)(x°-3x+4) : +ax°+ bx+c=x°-(y+3)x°+(3y+4)x-4y と表せる。両辺の係数を比較して [a=-y-3 6=3y+4 dDr fr+ 虚数解 a,a と実数解 をもつ3次方程式を立 式 5 2 lc=-4y ここで,aは整数であるから, ①より yも整数であることが わかる。このことと0SyS1であることから 8+S-- -= J キ)=D++。 Y=0または1 したがって, 求める整数の組 (a, b, c)は①~③より (a, b, c)=(-3, 4, 0), (-4, 7, -4) 答 1S+S.S- 実数解yを求める 解説 実数係数の方程式 f(x)= anx"+an-1.2"-1 + …+a1x+ao=0 が虚数解aをもつとき,それと共役な複素数αも方程式(*)の解である。 これは次のように証明できる。 お Cる

回答募集中 回答数: 0
数学 高校生

左側が問題、右側が回答です。 四角3番の(1)②の回答の式変形で±の符号がどのように変化しているのかがわかりません。教えてくだい。

(2) のは,結論の方が式が立てやすいので, 対偶を証明するとラクである。 を有理数と仮定すると, /2 は既約分数(p. qは整数, pキ0) と表せる(とく より p, qは自然数としてよい)。 このとき p, qは互いに素であるから、このこと 第1章 数と式, 問題させ、 第1章 数と式,集合と論理 3背理法 Lv.★★★★V の 第1回 解答は12ページ 考え方 2 は既約分数 p は整数, pキ0)と表せる(と を証明す 1 Lv.★★★ れ=1 2 を有理数と仮定すると, 9 = 3 次の問いに答えよ。 (1)a+6°+c° =1をみたす複素数a, 6, cに対して, x=a+b+cとおく。 このとき, ab+ bc+caをxの2次式で表せ。 2) a°+6°+c°=1, α+が+c°=0, abc = 3をすべてみたす複素数aん cに対して, x=a+b+cとおく。このとき,xー3x の値を求めよ。 て矛盾を導こう。 よって、 対偶 Process 解答 (1) ① 12 が有理数であると仮定すると V2= (ただし, pとqは互いに素な自然数) (早稲田大) 「N2は有理 Y/0 2 Lv.★★★ 解答は13ページ p と表せ と表せる。両辺を2乗すると にあてはまるものを, x, yを実数とする。下の(1), (2 )の文中の 次の(ア),(イ), (ウ), (エ)の中から選べ。 2= が 「分子は開散。 右辺に →= 2が 右辺は偶数であるから, q° は偶数,すなわち, qgも偶数である。 よって、q=2q' (g'は自然数) とおけて 2p= (2g)°=→ が3D2q'° がは偶数であるから, pも偶数である。すなわち, pもqも 偶数となり,pと qは互いに素であることに矛盾する。 したがって,仮定は誤りで, V2 は無理数である。 (証終) 2 aが有理数であると仮定すると りuも (ア)必要条件ではあるが,十分条件ではない。 (イ)十分条件ではあるが,必要条件ではない。 (ウ)必要条件であり,かつ, 十分条件である。 (エ)必要条件でも, 十分条件でもない。 本 よっ 「分母は偶数」 は 「分子と分はなわ に矛盾 とに) (1)x+y?<1は, -1<x<1であるための (2) -1<x<1かつ-1<y<1は, +y°<1であるための し 「aは有理数 (関西大図) 『=+(ただし、 sとtは互いに素な自然数) 3 Lv.★★★ 20 と表せる。aは α+α+1=0をみたすから いと 解答は14ページ を背 (+)+キ+ ニ=ーts±) (複号同順) 背 1=0→ t 与式に代入 次の各設問に答えよ。 (1)0 V2 が無理数であることを証明せよ。 ② 実数αがα+α+1=0をみたすとき, aが無理数であることを 証明せよ。 (2)0 nを自然数とするとき, n°が3の倍数ならば, nは3の倍数に なることを証明せよ。 ② ¥3が無理数であることを証明せよ。 国のせ さ すそ 理数 右辺は整数であるから, 左辺も整数でなければならず, s, tは 互いに素な自然数であるから、 t=1である。 よって、(*)より 00 土s°土s+1=0 → s(s°+1)3D1 sは自然数なので, sZ1, s"+1>1であるから(左辺)>1 となり、(右辺)= ±1に矛盾する。 (複号同順) 式を変形し、 したがって、仮定は誤りで、 αは無理数である。 (2) 0 対偶 (明治大) (証終) 8 14

回答募集中 回答数: 0
英語 高校生

答え合わせがしたいので教えてください

「I|次の文を読んで、あとの問いに答えなさい。( wのついた語は文末に注があります。 ns Sitting in the consultation room of a charming cosmetic surgery clinic in Washmgo. D.C., Hudson Young removed his mask under the satisfied gaze of his doctor. Like a grownns number of Americans, Young decided the right time to undergo plastic surgery was middle of a coronavirus pandemic, He knew he would have time to recover in the privacy ot his own home. The main reason, however, was that Young suddenly found himself face to face with his own image while participating in an increasing number of videophone and web A 「Its something new when you have to stare at your face for a couple of hours a day and there's only so much you can do with good lighting and good angles," Young said. The 52-year-old real estate agent had allready been a fan of cosmetic surgery. He had face lift, eyelid surgery and laser resurfacing for the first time in October. "When you see yourself on Zoom, you are shocked," he explained, as Dr. Michael Somenek examined his w barely visible scars. Young is far from the only one who has found himself disappointed with the reflection he has seen in the screen over the past year. Virtual consultations for cosmetic procedures have risen 64% in the United States since the beginning of the COVID-19 pandemic, according to the American Society of Plastic Surgeons. “We have seen an increase in the number of surgical cosmetic procedures that are directly related to Zoom," said Somenek, who has seen a 50% to 60% increase in customers. “I think the pandemic B has given everyone time to take care of those things that we've been putting off until later," explained Ana Caceres, who was able to work from home after C a plastic surgery operation she had wanted for a long time. She recovered at. her parents' house outside Washington after a December cosmetic surgery that helped her D deal with a source of insecurity she had had since adolescence. "I didn't have to days off, because I was still able to work from my bed with my lap-top," the 25-year-old said. “When life is going on and you have places to be, it's s0 easy to put things off," Caceres said, showing off a dress she says she now has the confidence to wear. And she has scheduled more cosmetic surgery. Her surgeon, Dr. Catherine Hannan, says consultations at her clinic in the IIS comit1 E have nearly doubled since the beginning of the pandemic. "Our patients have more lines because the last vear has been so hard. A face or boay change can have a psychological

回答募集中 回答数: 0
英語 高校生

教えてほしいです!!お願いします!!

問題は【1】~【4】まである。答えは各問題の指示に従って別紙の解答用紙に書きなさい。 【1】次の英文を読んで設問に答えなさい。 Headaches are a big problem. Each year, millions of people suffer from severe headaches that affect their enjoyment of life, (1) not to mention their productivity at work. estimate, headaches cost individuals and businesses more than (2) $50 billion each year! (3) This is one of the reasons research into headaches has become a worldwide effort. Although he did not know much about how headaches work, Hippocrates was the first doctor to find a way to treat them. By 400 BC, Hippocrates had discovered that the *bark from willow trees was useful in treating pain. He made a white powder from the tree's bark and gave it to his patients. Hippocrates did not know it, but he was actually prescribing a natural chemical in willow bark called salicin. Whena person eats salicin, the chemical is changed inside his or her body into (4) salicylic acid. It turns out that salicylic acid is good for stopping pain, including headache pain, but it is bad for a person's stomach. In the 1800s, a chemist in Germany slightly changed easier for people to take. commonly known as aspirin. Aspirin was used throughout most of the 1900s to treat headaches, but doctors had little idea about what really caused headaches. When doctors can *diagnose the cause of a disease, they can find better ways to treat it. Therefore, as medical technology developed, doctors began to use it to learn more about the human brain and about headaches. In fact, according to one m to make it This new form of the chemical was called acetylsalicylic acid, now acid's Now doctors classify headaches ( A ) two general types: primary and secondary. A primary headache is a condition ( B) as only the headache itself. one caused by another physiological condition, such as an *infection or a *tumor. For primary headaches, doctors have determined three possible causes. headache is caused by stress. characteristically felt on both sides of the head as a dull, steady pain. Another kind of primary headache is the *migraine headache. Exactly what causes these headaches is not well understood, but many experts believe it could be abnormal brain activity causing changes in the brain's chemistry and blood flow. For many people, migraines are caused by certain (5) stimuli, such as poor sleep or particular foods or smells. A sufferer usually feels intense pain on one side of the head and becomes sensitive to light and noise. If the migraine is severe, the sufferer may *vomit repeatedly. The third kind of primary headache is known as the cluster headache. Cluster headaches typically occur around the same time each day for weeks or months at a time. The person ( C)from this kind of headache usually feels pain on one side of her or his head, and the pain is centered around one of the eyes. Doctors do not know much (6) at present about cluster headaches, but they seem to be more common among men and could be related to alcohol or other things that affect a person's blood flow. Using computers and more advanced medical equipment, doctors continue to learn more about what happens in the brain before and during headaches. Especially in the case of migraines, some doctors believe they have found the part of the brain that sets off the reaction for severe attacks. With these insights into brain processes, doctors hope new ways will be discovered to stop headaches before they begin. On the other hand, a secondary headache is One kind of primary Doctors usually call these tension headaches, and they are 注: bark 樹皮 diagnose ~を診断する、~を突き止める 感染症·伝染病 migraine (headache) 偏頭痛 infection tumor 腫場 vomit 食べたものを吐く (出典:READING FOR THE REAL WORLD 3rd edition, Compass Publishing より)

回答募集中 回答数: 0
TOEIC・英語 大学生・専門学校生・社会人

これ読んだんですけど、自分は世界史を理解してなかったので分からなくて翻訳アプリ使ったんですけどそれでも分からなかったので分かる方できれば解読お願いします┏●

Denmark in World War II お んれ By Hannah Arendt Hannab Arendt (1906-1975) was a political scientist! and pbilosopber born in Hanover, Germany. Wben Hitler came to power, sbe was forced to leave Germany and came to the United States in 1940. Sbe continued ber academic career by lecturing and teacbing at arious colleges, including The New Scbool for Social Researcb in New York City. Among the many books sbe urote were Eichmann in Jerusalem, On Revolution, and The Origins of Totalitarianism. Editor's Insert During the Second World War. the Germans invaded Denmark in April, 1940. In the beginning of her essay, Hannah Arendt explains that of the four countries almost completely immune to anti-Semitism- Denmark, Sweden, Italy, and Bulgaria Denmark challenged its German masters directly. As soon as the German authorities talked about forcing Jews to wear the yellow badge,' the Danes replied that all Danish citizens, including the King, would be wearing it the next day if the policy were carried out. In addition, all Danish government officials threatened 舌は the German authorities with their immediate resignation if the Germans started to implement any anti-Jewish actions. The following excerpt from Eicbmann in Jerusatem shows how the Danes sabotaged the German plan to carry out the mass extermination of the Jews. only 2タカ人の What happened then was truly amazing; compared with what took place in other European countries, everything went topsy-turvey. In August, ー after the German offensive in Russia had failed, the Afrika Korns 1943 had surrendered in Tunisia, and the Allies had invaded Italy すgovernment canceled its 1940 agreement with Germany which had permitted German troops the right to pass through the country. Thereupon. the Danish workers decided that they could help a bit in hurrying things そのうえに up: riots broke out in Danish shipyards, where the dock workers refused to repair German ships and then went on strike. The German militarv commander proclaimed a state of emergency and imposed martial la and Himmler thought this was the right moment to tackle the Te the Swedish す。 (continued on next page) themselves as Jews secret police), and overseer of the concentration camps

回答募集中 回答数: 0
英語 高校生

英文4段落目3文目のno paintを塗られていないとなくしてしまいました、塗られていないだとしたらno paintedでしょうか?? またno paintは完全否定なんでしょうか、、??

第4問 次の問い(A· B)に答えよ。 (配点 33) will shrink considerably over time.、This shrinkage is caused by moisture not change size too much. But wood from a tree that has just been cut down (water) within the wood escaping into the atmosphere. The drying process of Wood used in the construction of homes must be stable. That is, it must A 次の文章と図およびグラフを読み,下の問い(問1~3)に対する答えとして 2012年度 本試験 15 roo に入れるのに最も適当なものを,それぞれ下の①~④のうち 37 35 fnnu yileub から一つずつ選べ。 19unolli bomisa odt bas boow boi basg es 9120m lo . known as “seasoning. There are actually two ways to season wood. r is to allow the natural drying process to occur. The other is to put it . cnecial oven called a kiln. Kiln drying is much faster than the natural method. During the seasoning process, water is removed from the wood until the moisture content of the wood is approximately equal to the humidity of the air around it. These changes in size due to shrinkage are not uniform because changes depend on the kinds of trees, the way trees are cut, and the surrounding conditions. It is also important to note that even after seasoning, there will always be Some small changes in size due to changes in the humidity of the surrounding air. For example, last year, I used a 230 mm wide piece of eastern white pine WOod to makea cabinet door. It changed in width across the grain (Figure 1), Shrinking by 2 mm from the original in the winter and expanding by 3 mm Ine moisture content of wood changes according to the seasons even niw= from the original in the summer. um volbsoH 8. -409

回答募集中 回答数: 0