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数学 高校生

複素数の問題です! どうしてk=0,1,2,3,4,5だとわかるんですか? 教えて下さい🙇🏻

例題 15 方程式 の解 極形式を用いて, 方程式2=1 を解け。 指針 次の手順で考えていくとよい。 ① 解を=r (cos0+ isin0) [r0] とする。 ②2 方程式2=1の左辺と右辺を極形式で表す。 CHART 複素数の累乗には また 解答 解をzr (coso+isin0) [r>0] とすると [3] 両辺の絶対値と偏角を比較する。 ・・・・・・・・・ ① 4 の絶対値と偏角の値を求める。0は0502の範囲にあるものを書き上げる。 ²°=r(cos60+isin60) 1=cos 0+isin0 (cos 60 + isin60) = cos0+isin 0 ① 両辺の絶対値と偏角を比較すると ro=1. 60=2k(kは整数) また >0であるから k r=1 k ド・モアブルの定理 (cosO+isin("=cosn0+isin n0 z=cos+isin...... よって 002の範囲で考えると k = 0, 1,2,3,4,5 ① で k=l(l=0, 1 2 3 4 5) としたときのとすると Zo=cos0+isin0=1, したがって 求める解は π /3 21-cos+isin = 1+1 3 2 0=1²3 r 8= 2₁= cos x+isinx=-12+¹2%. 23 = cosx+isinz= -1, z= cos x+isin x=-12-√31. COS 5 ① 5 2008/13tisin 1/17-12-1221 √3 25 = COS R= 3 ■P.29 基本事項 [2] z= ±1 ± i +1+¹/3; 土 ・i 2 2 00000 重要 17.19. ド・モアブルの定理。 1を極形式で表す。 z=1 の両辺を極形式で した。 (検討 2-10から (z+1)(z-1)(z²+z+1) x(z-z+1)=0 このように, 因数分解を利 して解くこともできる。 なお,解を複素数平面上に 示すると、 単位円に内接す 正六角形の頂点となってい また、 が成り立つ → p.36, 37 の参考事項も 照。 y4

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英語 高校生

答えがなく困っています。 どうかよろしくお願いします。

Ⅰ 次の英単語で最も強く発音する部分(第一アクセント)を、 それぞれ記号で答えなさい。 d 2. a-bil-i-ty 3. access 4. va-ri-e-ty 5. in-tro-duce del-i-cate アイウ アイウェ アイ アイウェ アイウ Ⅱ 次の英文を読み、 設問に答えなさい。 How many hours a day do you spend on your *cell phone? Today, more and more young people are spending more and more time on smartphones and computers. According () a 2013 *survey carried out by the *Japanese Cabinet Office, 97.2% of high school students owned a cell phone; of these, 82.8% had a smartphone. This is a *drastic increase from 2010, when only 3.9% of those with cell phones had smartphones. The survey also shows that the spread of smartphones has led to increased access to the Internet among children, whose average access time on a weekday is 107 minutes. The Cabinet Office also found that 40% of Japanese children *log on to the Internet more than two hours a day, and that 8% spend more than five hours a day online. This has led to some serious social and *psychological problems. Heavy Internet users become *obsessed with staying online and develop an *addiction to games, social media sites, and free communication systems such as LINE. The various *adverse effects of such addictions have been reported in most developed countries. Many young addicts suffer (2) headaches and sleep disturbances such as *insomnia. They fail to maintain normal weight *due to eating irregularities. And many are more likely to experience emotional distress, isolation, anxiety, and depression. A British study suggests a clear link between excessive Internet use (3) lower self-esteem. Those young people who spend more than A four hours a day looking at a screen are particularly *vulnerable to mental *disorders. -No H Several related studies conducted in China make clear the effects of Internet use on brain structure. One study has shown that *volume @losses were seen in the *gray matter areas of Internet addicts' brains. These areas are involved in people's ability to develop *empathy and compassion for others. Another Chinese study used MRI scans to look at the brains of Internet-addicted teenagers and found significant damage in the *white-matter nerve fibers connecting the brain areas governing emotions, decision-making, and self-control. Similar (4) can be seen in the brains of heavy alcohol and drug users. () cell phone: ## survey: drastic: 極端な log on: アクセスする obsessed with ~ : ~に夢中になる addiction due to~: ~のため volume: white matter: insomnia: TRE disorder: , empathy: # 1. ( ) ①~④に入れるのに最も適した語をそれぞれ一つずつ選び、その記号で答えなさい。 (with into A to = at) 2 ( from = above) □in Japanese Cabinet Office: A psychological: 心理的な . # adverse effects: vulnerable to~: ~になりやすい gray matter: K ハon

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