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数学 高校生

⑵のtanΘ=tan 2✖️tan2分のΘの次の変形がわかりません。なぜこうなるのか教えていただきたいです🙏

纈羽 11 <<x, sino=2のとき、 (1キ±1)のとき、次の等式が成り立つことを証明せよ。 (2)t=tan anma 21 sin@= cos 0= 1+12, 1+t2" tan 0= 2t 1-t2 (1) S 指針 (1)2倍角、半角の公式を利用する。 また sin 20, tan p.247 基本事項 の値を求めるには、COS8の 値が必要になるから、かくれた条件 sin'0+ cos'01 を利用して、この値も求め ておく。 (2)02-22 であるから、2倍角の公式を利用。tan0 →coso の順に証明 する。 tan と coseが示されれば, sin0 は sin0=tanAcos0 により示される。 (1) cos20=1-2sin20=1-2・ T << であるから 100 32 18 7 =1 cos0=-√1-sin'Q=- 1 移るような 3 ゆえに π π 日 << より 4 2 2 1-cos よって tan sin20=2sinOcos0=2. < < であるから 1+cos 0 √ 5-4 5 = 25 25 32 35 == 4 0は第2象限の角であ るから COSA<0 5S200 4-5 24 25 225 指針 解答 解答 0 tan 5+4 =3 hiaS-I- 2 tan (2) tantan 2• 02 0 2 2t = =- (t±1) 200 1-tan²- 0 1-t2 2 日 1 1+tan². 0 1 2 から COS 2 0 COS2- 2 26 1+tan². 1+t2 2 よって cosO=cos2=2cos2- 0 0 2 -1= 1-t2 点が 2 1+t -1- = ゆえに sin0=tan0cos0= 2t 1-t2 2t • conia(1-12 1+1² 1+12 = 1 5+4 V 5-4 = √9 晶検討 sin=s, cost tan1/2=1=12 1+2 これを証明する等式の 右辺に代入して s2+c2 = 1 などから、左 辺を導くこともできる。 おくと tan

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英語 高校生

vision questⅡ English expression hope 70ページ preview 1.date&time 2.numbers(sizes,measurements,etc) 3.prices&Phone numbers listeningtask 1.... 続きを読む

140 // TIT Activity for Communication 3 Preview Listen to the sentences below. 1 Dates & Times Listening for Numbers the on Enio 1. "The movie starts at 5:20. Can you be ready in ten minutes?" "OK. I'll try." 2. "What time is it now?" "It's 11:30." basalaila awohlsw 3. I have an appointment with the dentist this Thursday, the 10th. M 4. "When does school begin?" "It begins on April 8th." 5. Our school was established in 1965. 6. My family has lived in this town since 2005. 2 Numbers (sizes, measurements, etc.) 1. Two thirds of the students come to school by bus. 2. One mile is about 1,609 meters. 3. The city has a population of about 2.5 million. 4. The temperature dropped to 12°C. 5. APA Air Flight 125 for London will be departing from Gate 14 at 10:15. 3 Prices & Phone numbers 1. The price of this bag is $27.89, but you can have it at 10 percent off. 2. What would you do if you won 100 million yen in a lottery? 3. "A hamburger and a cola, please." "That'll be £2.99." 4. I need €20, but I'm €5 short. 5. My phone number is 612-750-5613. Listening Task Listen to the conversations and choose the correct answers. 1. How much of the earth's surface is covered by ocean? 1 more than one third more than one fourth 監督署 ER 70 3 more than two thirds 4 more than two fifths 2. When were the Olympic Games held in Atlanta? 1 in 1966 2 in 1969 3. How much did the dress cost? 1,100 yen 2 1,800 yen 3 in 1996 4 in 1999 S 8,000 yen ③ 13,000 48,800 yen bluros ④ 30,000 about 200,000 4. How many people can the concert hall hold? ① 1,300 ② 3,000 5. How many people live in the city? ①about 2,000 2 about 12,000 3 about 20,000 ① 207-7300 2207-7003 ③ 702-3300 6. What's the phone number of the restaurant? The number is 510- ④ 702-3003

解決済み 回答数: 1