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数学 高校生

133. xを求めてからの解答までの導き方はこれでも大丈夫ですかね??

208 重要 例題 133 解が三角関数で表される2次方程式 -8.201+00 aを正の定数とし,0を0≧0≦を満たす角とする。2次方程式 2x²-2(2a-1)x-a=0の2つの解が sine, cos 0 であるとき, a, Sin, Cos 040 nie 020000 値をそれぞれ求めよ。 指針 2次方程式の解が2つ与えられているから, 解を代入の方針でなく 解と係数の関 係 を利用するとよい。 解と係数の関係から 解答 与えられた2次方程式に対し, 解と係数の関係から sin0+cos0=2a-1 ①, 練習 a 2 sin Acos0=- ① の両辺を2乗して sin²0+2sinocoso+cos20=(2a-1) 2 E&SHO sin²0+ cos20=1 であるから 1+2sinAcos0=(2a-1)2 これを解いて a sin+cos0=2a-1, sincos =) ( 200 TO BE しかし,未知数は3つ (a, sine, cos e) であるから, 式が1つ足りない。 そこで,かくれた条件sin²0+cos'0=1 も使って, a についての2次方程式を導き, そ を解く。 なお, sin0 または cose の範囲に要注意! (Coisc 200+ C²# AB これに ② を代入して -2.(-2)=4a² =4a²-4a+1 よって 4a²-3a=0 すなわち α(4a-3)=0 pos/3 a>0であるから a=² 4 このとき, 与えられた2次方程式は 2x2-x- -=0 すなわち 3 4 1+2・ cos+1+√7 x= 4 (2) また 0≦O≦xのとき, sin0≧0であるから sin0= -01-√7 <0<===>> 1+√7 8x2-4x-3=0 0805 S 解と係数の関係・ 2次方程式 ax²+bx+c=0の20 解を α, βとすると 2015 (8800 nia a+B==₁ aß= 1+√7 cos8=1-√7 4 21008305 30nia TAH sino+coso 0000 0 2000 ie$+0 nie =0 2000 miest 065070200 00 -2(2a-1) == 「複雑な方 2 を変更 E [□] 133(cosA>sin0,0 <6<²) で表されるとき,の値と sing ponia-0°niz) (0 200+aiz)=600+0'nia EVO (1 基本 sin' + ens' =1. 0 2000 mie 3130 右の大がかれた。 x= 8x²-2-2x-3=0 であるから 0 2±2√7 8 = 1+√7 4 2±√(-2)^2+8.3 8 2014 (17 SCOVER kは定数とする。 2次方程式 25x2-35x+4k=0の2つの解が in cos 082 ③83 084 085 HI

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英語 高校生

教えて下さると嬉しいです( •̥-•̥ )

A. Circle the correct answer for each question. likely to be jealous of someone. 1. You are more 2. Which do many people decorate at Christmas time? 3. Which are people more accustomed to? a. rich a. a feast b. a tree a. spending money b. receiving awards a. an empire b. a rifle a. an insect b. water a. help it b. ruin it 6. What would profit do for a business? a. excited b. confused 7. Which would people rather be? a. a contract b. a feast 8. Which would you invite friends to share with you? a. a recruit b. a contract 9. Which would you sign? a. being punished b. getting a reward 10. Which would few people enjoy? B. Complete the paragraph with items from the box. Two items are extra. Which of these is a weapon? 4. 5. Which of these flows? discovered resembled establishing rights faced status by Roy's s grief the rest of Many people change countries during their life, but one man has (1) (2) son and (10) heir took over This surprised people in the UK, who believed they had the (5) . Bates and (6) to leave the platform. However, Roy (8). in the sea to contain (3) that would be used to fight off invaders. After the war, the soldiers left these platforms and they were forgotten - until 1967. In that year, a British man, Roy Bates, one of the platforms and announced he had started his own country, (4) called Sealand. b. poor himself by his own country. During World War II, the UK built a number of artificial platforms made a name for weapons the people on the island (his family), (7) In 1968, a court decided that the UK had no power over Sealand. Just like other places with the that the platform was in international waters. to the platform. orders of a country, Sealand, has its own stamps, coins, and passports. It is controlled 'Prince' Michael, and is home to a large Internet business. 11 15 69

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英語 高校生

教えて下さると嬉しいです(><)

Circle the correct answer for each question. A. likely to be jealous of someone 1. You are more 2. Which do many people decorate at Christmas time? 3. Which are people more accustomed to? 4. Which of these is a weapon? 5. Which of these flows? a. rich b. poor a. a feast b. a tree a. spending money b. receiving awards b. a rifle b. water b. ruin it b. confused b. a feast b. a contract a. a recruit a. being punished b. getting a reward B. Complete the paragraph with items from the box. Two items are extra. 6. What would profit do for a business? 7. Which would people rather be? 8. Which would you invite friends to share with you? 9. Which would you sign? 10. Which would few people enjoy? discovered resembled establishing rights faced status a. an empire a. an insect a. help it a. excited a. a contract grief the rest of (9) by Roy's son and (10) heir took over Many people change countries during their life, but one man has (1) (2) himself by his own country. During World War II, the UK built a number of artificial platforms in the sea to contain (3) that would be used to fight off invaders. After the war, the soldiers left these platforms and they were forgotten - until 1967. In that year, a British man, Roy Bates, (4) one of the platforms and announced he had started his own country, called Sealand. This surprised people in the UK, who believed they had the (5) - Bates and (6) to leave the platform. However, Roy (8). made a name for weapons to the platform. orders In 1968, a court decided that the UK had no power over Sealand. Just like other places with the that the platform was in international waters. of a country, Sealand, has its own stamps, coins, and passports. It is controlled 'Prince' Michael, and is home to a large Internet business. the people on the island (his family), (7) in 11 - 15 69

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英語 高校生

教えて下さると嬉しいです(><)(><)

A. Circle the correct answer for each question. likely to be jealous of someone 1. You are more 2. Which do many people decorate at Christmas time? 3. Which are people more accustomed to? a. rich a. a feast b. a tree a. spending money b. receiving awards a. an empire b. a rifle a. an insect b. water a. help it b. ruin it a. excited b. confused a. a contract b. a feast a. a recruit b. a contract a. being punished b. getting a reward B. Complete the paragraph with items from the box. Two items are extra. 4. Which of these is a weapon? 5. Which of these flows? 6. What would profit do for a business? 7. Which would people rather be? 8. Which would you invite friends to share with you? 9. Which would you sign? 10. Which would few people enjoy? discovered resembled establishing rights called Sealand. faced status - Many people change countries during their life, but one man has (1) (2). This surprised people in the Bates and (6) to leave the platform. However, Roy (8). (9) by Roy's son and (10) grief the rest of heir took over in the sea to contain (3) that would be used to fight off invaders. After the war, the soldiers left these platforms and they were forgotten - until 1967. In that year, a British man, Roy Bates, one of the platforms and announced he had started his own country, b. poor himself by his own country. During World War II, the UK built a number of artificial platforms made a name for weapons who believed they had the (5) the people on the island (his family), (7) to the platform. orders In 1968, a court decided that the UK had no power over Sealand. Just like other places with the that the platform was in international waters. of a country, Sealand, has its own stamps, coins, and passports. It is controlled 'Prince' Michael, and is home to a large Internet business. in 11-15

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英語 高校生

教えて下さると嬉しいです。。涙

Circle the correct answer for each question. A. likely to be jealous of someone 1. You are more 2. Which do many people decorate at Christmas time? 3. Which are people a. rich a. a feast a. spending money b. receiving awards a. an empire b. a rifle a. an insect b. water a. help it b. ruin it a. excited b. confused a. a contract b. a feast a. a recruit b. a contract a. being punished b. getting a reward B. Complete the paragraph with items from the box. Two items are extra. 4. Which of these is a weapon? 5. Which of these flows? more accustomed to? 6. What would profit do for a business? 7. Which would people rather be? 8. Which would 9. Which would you sign? 10. Which would few people enjoy? discovered resembled you invite friends to share with you? called Sealand. establishing rights faced status grief the rest of Many people change countries during their life, but one man has (1) (2) heir took over (9) by Roy's son and (10) This surprised people in the UK, who believed they had the (5) . Bates and (6) to leave the platform. However, Roy (8) - b. poor in the sea to contain (3) that would be used to fight off invaders. After the war, the soldiers left these platforms and they were forgotten - until 1967. In that year, a British man, Roy Bates, one of the platforms and announced he had started his own country, b. a tree himself by his own country. During World War II, the UK built a number of artificial platforms the people on the island (his family), (7) - - made a name for weapons to the platform. orders In 1968, a court decided that the UK had no power over Sealand. Just like other places with the that the platform was in international waters. of a country, Sealand, has its own stamps, coins, and passports. It is controlled 'Prince' Michael, and is home to a large Internet business. im 11 - 15

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