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数学 高校生

(2)でzが+-1とそうでない時で場合分けをしていますが、絶対値が1なら必ず+-1になるのではないのですか?

総合 絶対値が1で偏角が0の複素数をぇとし, nを正の整数とする。 17 (1) 1-220で表せ。 (2) 22k を考えることにより, sin2k0 を計算せよ。 本冊数学C例題 108, 133 k=1 k=1 (1) z=cosQ+isin0 であるから |1-22|=|1-(cos 20+isin20)| = √(1-cos 26)2+sin'20 =√ どうにかして ←ド・モアブルの定理。 [√を外す方法を 考える √2-2cos20=√2-2(1-2sin'0) ←sin 20+cos220=1, cos20=1-2sin20 =√4sin20=2|sin 0| k=1 k=1 k=1 n n よって, sink日はΣz2kの虚部である。 k=1 k=1 n (2) = (cos 2k 0+isin 2k 0)= cos 2k0+i sin 2k0 “= n ←ド・モアブルの定理。 k=1 z2k=(cos0+isin O) 2k =cos2k0+isin2k0 k=1 n [1] z=±1のとき, 22k は実数であるから sin2k0=0 [2] z±1 のとき, z2≠1であるから k=1 2n+2 224=222(22)1_2211-(22)"} 22-221 k=1 k=1 1-z² 1-22 (22-22n+2) (1-22)(22-22n+2){1-(Z)"}←(1)の結果を利用する = (1-22) (1-22) z²+z2n-z 2n+2-1 |1-22|2 ために,分子・分母に 1-2 を掛ける。 また, |zz=|z=1にも注意。 ←z=±1のとき = (n は整数) ←等比数列の和の公式。 22-21-22n+2+1zz2n (2|sin0|)2 4sin20 ( ここで, 22+22n-z2n+2-1の虚部は sin 20+ sin 2n0-sin(2n+2)0 54202251400050 =2sin(n+1)0xcos(n-1)0-2sin(n+1)×cos(n+1)0 =2sin(n+1)0{cos (n-1)0-cos(n+1)0} =2sin(n+1)0{-2sinnOsin(-9)} =4sinOsinnQsin(n+1)0 であるから n Σsin 2k 0= k=1 4sin OsinnOsin (n+1)0_sinn0sin(n+1)0 n 4sin20 sino [1], [2] から, sin2k0 の値は,n を整数とすると ←ド・モアブルの定理。 ←sina+sinβ =2sin a+β a-B COS 2 2 cosa-cos β a+B a-B =-2sin- -sin 2 ← 22k の虚部 [1] k=1 2 k=1 0n のとき 0, 0πのとき sinn0sin(n+1)0 sin A [s] A fic

解決済み 回答数: 1
英語 高校生

この文の下から8行目のstream jumping とはどういう訳し方が正解ですか?

B You are reading the following article as you are interested in studying overseas. Summer in Britain Chiaki Suzuki November 2022 This year, I spent two weeks studying English. I chose to stay in a beautiful city, called Punton, and had a wonderful time there. There were many things to do, which was exciting. I was never bored. It can get expensive, but I liked getting student discounts when I showed my student card. Also, I liked window-shopping and using the local library I ate a variety of food from around the world, too, as there were many people from different cultural backgrounds living there. Most of the friends I made were from my English school, so I did not practice speaking English with the locals as much as I had expected. On the other hand, I came to have friends from many different countries/ Lastly, I took public transport/which I found convenient and easy to use as it came frequently. If I had stayed in the countryside, however, I would have seen a different side of life in Britain. My friend who stayed there had a lovely,/relaxing experience. She said farmers sell their produce directly. Also, there are local theatres bands, art and craft shows restaurants, and some unusual activities like stream-jumping. However, getting around is not as easy, so it's harder to keep busy. You need to walk some distance to catch buses or trains, which do not come as often. In fact, she had to keep a copy of the timetables. If I had been in the countryside, I probably would have walked around and chatted with the local people. I had a rich cultural experience and I want to go back to Britain. However, next time I want to connect more with British people and eat more traditional British food. Day 08 2023年度: 共通テスト追試験 第2問B 115

解決済み 回答数: 2
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