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数学 高校生

矢印の場所がわかりませんどんな変換をしているのですか?

256 基本 例題 158 和と積の公式 基 0≦ (ウ) cos 20°cos 40°cos 80° (1)積→和,和→積の公式を用いて、 次の値を求めよ。 (ア) sin 75°cos 15° (イ) sin 75°+sin 15° (2) △ABCにおいて、次の等式が成り立つことを証明せよ。 解答 8-A #sin A+sin B+sin C=4 cos- A B 2 2 COS COS 2 指 8-AOA P255 基本事項 ② 重要 167 指針 (2) △ABCの問題には, A+B+C= (内角の和は180°) の条件がかくれている。 A+B+C= から, 最初にCを消去して考える。(+200) そして,左辺の sin A + sin Bに和→積の公式を適用。 (1) (ア) sin 75° cos 15°= 1 sin(75°+15°) +sin(75°-15°)} (2)<< = 2 1/12(sin90°+sin60°)= のと /3 1/(1+ √3)=2+√3 4 75°+15° 75°-15° ・COS 2 2 解 =// 1 97 ZA = cos 80°+ 4 1 1 2 2 (イ) sin 75°+sin15°=2sin =2sin45°cos 30°=2. 1 2 2 2 (ウ) cos 20°cos 40°cos 80°= -{cos 60°+cos(-20°)}cos 80° 1214 (-b) ai++ )aia) -8200nta + cos 20° cos 80° 30°=1/13cos80°+1/2/cos 20°cos 80° 4 1 1 1 {cos 100°+cos(60°)}=11 icos 80°+ cos 100° + 4 8 (1) (2) A+B+C=πから C=(A+B) ゆえに =1/cos80°+1/cos(180°-80°)+1/31/cos80°-1/2COS80°+ 4 8 8 sinC=sin(A+B), cos=cos(A+B) - sin A+B 1 1 4 4 2 のと よって sin A+ sinB+sinC=2sin A+B A-B A+B COS +sin2. 2 2 2 (8+ A+B =2sin + 2 COS A-B 2 +cos A+B) C 2 =2 cos 2 cos cos(-) A B COS 2 2 +=4cos 800 2 A COSCOS B C 2 練習 (1) 積和,和→積の公式を用いて, 次の値を求めよ。 (イ) cos 105° - cos 15° ③ 158 (ア) cos 45° sin 75° (ウ) sin 20°sin 40° sin 80° (2)△ABCにおいて,次の等式が成り立つことを証明せよ。 99 0 cos A+ cos B-cosC=4cos- A B cossin-1 2 p.270 EX 100

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英語 高校生

あっていますか?💦

BWA 1 With approximately 200 countries and 8 billion people on earth, it is not hard to imagine that many diverse cultures exist. Here in the U.S., our cultural landscape has been shaped by Native Americans and by African, Latin American, Polynesian, Asian, and Middle Eastern countries. This is the reason that the term "melting pot" fits our country, as different cultures have contributed distinct flavors. 2 5 Like many others, I came to this country when I was young, in my case in my twenties. While we adapted to most cultural norms here in the U.S., some of us have kept a few from our origin. This has been the marvel of this country; it lets you assimilate easily into its culture, while you keep your distinct identity. To me, cultural diversity means merging different cultures-introducing good aspects of your culture to others, but 10 also incorporating the superlatives of a new culture. 3 Culture shapes our identity and influences our behaviors. Also, cultural diversity makes us accept, and even to some extent, integrate and assimilate with other cultures. Cultural diversity has become a key buzzword in today's world. Whether we work or study or even stay at home, our chances of interacting with people from various races, 15 ethnic groups, and cultures are far more prevalent now than they have been ever before. 4 By learning about people of different cultural backgrounds, we can expand our horizons, have better interpersonal dialogue and communicate more on a personal level. If you put aside any prejudices or biases you might have, and you are open to other people, it can help prepare you to listen, talk and learn about other people and their 20 cultures. 35

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