数IIについて 　「方程式の実数解をαとする」の部分で、置きかえるのはどうしてですか。

x の方程式 (1+i)x2+(k+i)x+3+3ki = 0 が実数解をもつように,実数k の値を定めよ。 また, その実数解を求めよ。 基本 38 CHART & SOLUTION 2次方程式の解の判別 判別式は係数が実数のときに限る 解答 方程式の実数解をα とすると D≧0 から求めようとするのは完全な誤り (下の INFORMATION 参照)。 実数解を α とすると (1+ i) a²+(k+i)a+3+3ki=0 この左辺をa+bi (a, b は実数) の形に変形すれば, 複素数の相等により a=0, b=0 ← α, k の連立方程式が得られる。 ←置きかえるのは どうして? 784) 複数が合されている (1+i)a²+(k+i)a+3+3ki=0 ...... x=α を代入する。 整理して (a²+ka+3)+(a²+a+3k) i=0 ←a+bi=0 の形に整理。 α, k は実数であるから, Q2+ka + 3, a²+α+ 3k も実数。この断り書きは重要。 よって a²+ka+3=0 ◆ 複素数の相等。 a²+a+3k=0 ① ② から ゆえに よって [1] k=1のとき ① ② はともに α2+α+3=0 となる。 これを満たす実数 α は存在しないから、不適。 [2] α=3のとき ①,②はともに 12+3k=0 となる。 ゆえに k=-4 [1], [2] から 求めるkの値は 実数解は (k-1)α-3(k-1)=0 (k-1)(a-3)=0 k=1 または α=3 ONE 2次方程式には適用できな k=-4 x=3 De ← α2 を消去。 inf を消去すると α3-2²-9=0 が得られ, 因数定理 (p.87 基本事項 2 を利用すれば解くことがて きる｡ ←D=12-4・1・3=-11< ← ①:32 +3k+3=0 ②:32+3+3k=0 INFORMATION 2次方程式 ax²+bx+c=0 の解を判別式 D=62-4ac の符号によって判別できる のは a,b,cが実数のときに限る。 例えば,a=i, b=1,c=0 のとき -4ac=1>0 であるが, 方程式 ix2+x=0 の解 異なる2つの実数解をもたない (p.85 STEP UP 参照)。

aとb教えて欲しいです。 お願いします🙇

1 a comma [] + which/who: Giving extra information with a relative clause -関係代名詞の非限定用法 Ex.1. We first flew to the Netherlands, which is famous for its tulips and windmills. Ex.2. My sister, who now lives in Indonesia, is a programmer. The Netherlands Indonesia Q. Complete the following sentences by giving extra information with which or who. @ In the near future, I want to visit (the name of a city or country), which ... In the near future, which I want to visit Australia I read a book about (the name of a person), who ... I read a book about Hib

「中学生は新聞を毎日読むべきか。賛成か反対か」 5文程度 I agree. I have two reasons. First,reading newspaper can get many informations. Second,I think that became ... 続きを読む

「中学生は携帯電話を持つべきか。賛成か反対か」 5文程度で I agree. That’s because we have to get on touch when we need. For example,most junior high school students... 続きを読む

誰か採点してくださーい🙌🙌

よく出る 4 次のinformation literacy skills (情報リテラシー: 自分が必要とする情報を見きわめて入手し、 活用する力)についての英文を読んで、あなたの考えを、〔条件〕と〔記入上の注意】 に従って40 語以上50語程度の英語で書きなさい｡ ( 10点) People need information literacy skills. Some people say that every elementary school student should start learning these skills at school. What do you think about this idea? [条件] 質問に対する自分の考えを、その理由が伝わるように書きなさい。 〔記入上の注意] ① 【記入例】にならって、 解答欄の下線 _ 符号(,.?! など)は語数に含めません。 50語を超える場合は、解答欄の破線 Hil America. in rarint egur Ⅰ am bro asilbond ne ② 英文の数は問いません。 ③ 【下書き欄】は、必要に応じて使ってかまいません。 yart san sustoig tigl 【記入例】 【下書き欄】 is I'm Where April is Ken's birthday, too. of noilasup の上に1語ずつ書きなさい。 l で示された行におさまるように書きなさい。」 A og so lot zo ei sil 10:8 Nancy. are 2. I'm you 2001. from from? It 50 405 50 8 NOW S 平成31年■ (41)

英検準一級です Should people trust information on the internet? でライティングしました。 添削お願いいたします。

I don't agree that people should truse information on the Internet. This essay will explain the two main reasons for my opinion Th Terms of News and online shopping The first reason is that we cante lonow that the news 75 correct. Although we are able to obtain a variery of Information, the news may have a hias. A tending may suffer to us such as There fore, I found that A tending information the big earthquake in Kumamoto. don't have to rely to everything. we For example, when The second reason is the online shopping is likely to send we buy the dress through internet, goods which we down requine. we can't know whom this dress sell by. If it were not for buying clothing ac online store, it could not have such a opportunity to purchaseing different clothing. For these reasons, I don't believe people ought not to trust information. on the Internet.

英作文の問題の回答の添削をしてもらいたいです。 こうした方がいいなどのアドバイスもあればお願いします。

Because It is Nursery school. I think Recause you have alittle brother so you are good at taking care of children. The intership will be very hard but very fun.

答えがウなのですが、なぜアは違うのでしょうか？

設問A 次のEメールを読み、 空所 ①~⑤を補うのに最も適当なものを1つずつ選び、 記号 で答えよ。 Professor John Smith, Good evening. I am sending this e-mail to you because I have something to ask about the report we have to hand in on Monday. In the last class, you said that it would be all right for us to send you an e-mail this weekend 1 the report. Actually, I'm afraid that I can't finish it by the deadline because yesterday I home some books from the library to finish my report. So, I had to use the Internet, 3 ]. When I searched the Internet for information to finish my report, I realized there was too much information, and I couldn't decide which was correct and reliable. Then I realized I needed to change my topic. I am very happy if I can change my topic to 4 I hope to hear from you soon. 6 Taro Yamada 2 (7) forgot bringing (1) forgot to take didn't bring (I) took them

青い星印をつけた箇所について質問です。 なぜtell other people about themがダメなのかもう少し詳しく説明お願いします🙏

20 例題42 だれでも自分の考えを持っているが、それを他 Disk2 トラック 35 人にわかるように伝えるのは難しい。 たいていの場合、 あまり 簡潔に言うよりも、 例を挙げたり根拠を示したりして説明する 方がいい。 [大阪女子大学]

問5で(3)の訳が問われているのですが なぜafter等もないのに4時間"後"と訳せるのですか？

試験本番でのこの本での 目標時間 目標時間 Lesson 4 103 次の英文を読んで、後の問1~5の設問に答えなさい(固有名詞はそのまま使用し てよい)｡ 5 15 分 分 22 分 ◆解答・解説本冊 p.6 Here's a possible strategy to boost" memory-exercise four hours after you learn something. In a study published in the July 11, 2016, Current Biology, researchers found that exercise after learning may improve your memory of the new information, but only if done in a specific time window *2. (In the study, 72 participants learned 90 picture-location associations mentally linking an image with new information in order to improve recall over a 40-minute period. They were then randomly assigned to one of (1) three groups: one group exercised immediately, the second exercised four hours later, and the third did not exercise. The exercise routine consisted of 35 minutes of interval 10/training on a fitness bike at an intensity of up to 80% of maximum heart rate. After 48 hours, the participants' memory was tested while their brains were scanned*4 via MRI*5. Those who exercised four hours after the learning session retained*6 information better than the other two groups. The MRI also showed the hippocampus, the brain region involved with learning and memory, - that (2) 15 was more active when information was recalled correctly. Newly learned information turns into long-term knowledge through a process that requires certain brain chemicals that are released during exercise, but more research is needed to understand (3) this phenomenon. (4) It is also not clear why four hours was more beneficial, or if another time frame might produce a similar 20 effect.