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

(6)がわかりません practice the piano を it に変えた場合なぜtheはなくなるのですか？

⑤5 次の表は,けい子の今週後半から来週前半の予定を表したものです。 表を見て,英文や対話文の空所 に適する語を書きなさい。 (4)~ (6)は1語とは限らない。 □(1) Keiko Thursday. Go gaio 口 (2) Keiko and her mother tennis next COMES TO a cake next Tuesday. □ (3) A: Is Keiko going to do her homework next Friday? B: 木金土日 □ (6) A: When is Keiko going to practice the piano? B: She 月 ④ A: What are Keiko and her father going to do next Saturday? B: They □(5) A: Who is going to come to Keiko's house next Sunday? B: クラブ活動 (テニス) fit 宿題 (読書感想文) 父とサッカー観戦 (横浜) Elmo T) 火 母とケーキ作り Os s 美香 (Mika) が遊びに来る ピアノの練習 in Yokohama. E

高校生英語です。 ビジョンクエストとtry it out Lesson7がわからないので教えてください。

Try it out 1 Which word fits best? 1. (Encouraged / Encouraging ) by an American teacher, I applied to a college in the U.S. 2. ( Talk / Talking) with the international student, I found myself enjoying speaking English. 3. (Whether / Although) the pronunciation of the word was difficult, I made myself understood. 4. He was proud (to / that ) win the speech contest held last week. 5. ( Unfortunate / Unfortunately ), our group lost the debate about how to protect minority languages. 6. He was reading a newspaper with his legs ( crossing / crossed ). Lesson 7

(21)の答えが3になるのがなんでか少し分からないです…わかる方いますか？？

(21) (22) (23) Any Change? Long ago, humans did not use money. Because they often could not produce everything that they needed, they traded some of their goods for goods made by others. Gradually, the goods that they exchanged were replaced by cash. For hundreds of years, metal coins and paper bills that can be exchanged for goods and services have been produced. Cash is convenient for many people because it is easy to carry. At the same time, though, it ( 21 ). Another disadvantage is that criminals have been able to produce fake coins and bills. In the middle of the 20th century, plastic credit cards were introduced. They had security features to prevent them from being used by anyone except their owners. At first, their use was limited to wealthy people. Over time, however, they became ( 22 ). In the last few years, apps for smartphones that can be used in the same way as credit cards have also become popular. Because of this, some people are suggesting that we may soon see the end of cash. Supporters of a "cashless" society in which all payments are made electronically argue that it would have several benefits. For example, people would not have to worry about keeping their wallets safe. However, some people are concerned that they might be unable to pay for the things they need because of a software error or a broken smartphone. Moreover, some people do not have bank accounts or credit cards, so their only option is to use coins and bills. ( 23 ), it seems as though societies will continue to use cash. 1 can be lost or stolen can be recycled 1 thinner and lighter 3 harder to use 1 For now 2 Until then 2 4 2 4 3 is used for shopping online is understood by almost everyone more colorful and exciting more widely available With luck 4 By contrast

…②の解き方教えてほしいです！ ちなみに　x=2y になります。

y = = 1/(x+y) 3 (x+y) station by car, but Orfitz + 200 20+ 210 ・② 21〃=210

教えてください🙏

5. First, we'll have dinner. (A) Still 6. The 7. (A) debt (B) Though of the party is over there. Let's say hello to him. (B) host (C) resort (D) job we'll take a walk along the river. (C) Even have to exercise a lot and watch what they eat. (B) Athletes (A) Benefits 8. Tokyo and Osaka have great and buses. (A) transportation (B) stadium (D) Afterwards (C) Improvements (D) Concerts systems. Both cities have many trains (D) building (C) competition

数IIIの積分に関する問題です。 写真の問題を教えてください。

次の等式を満たす関数f(x)を求めよ。 fox)=ext Stfit)dt

（１）から（４）2次不等式の解き方あっていますか？間違っていたら解き方と答えを教えてほしいです。

(1) 2²³² - 4x + 6 > 0 D = 16-24 = -8 <0. (x - 2)² + 270 FIF 17 IN 2011 (4) 2 x ² + 4 9 + 3 ≤0 0=0. 2(x+1)+1c0 Fit Tin (2)2²-4x+6=0 D<.0 (x - 2)² + 2 = 0 解はすべての解 (3) 22^²+4x+320 D = (6-24 = -8 <0 ( 2 (2+1)²²³4 1 20 IF TEU

この丸で囲った顔つきってどこからくるのですか？

次の英文の下線部を訳しなさい with a series of negatives. In Tokyo I am not worried even if I walk When I try to explain why I am happier in Tokyo I generally beg down a dark street late at night. In Tokyo the subway cars are not defaced with graffiti or filled with people who look as if they might suddenly resort to violence. Ide duke I RT 「まるで〜みたい

2つの問題、私が答えた回答は合ってますか？ また合っていなければ解説お願いします🙇‍♀️

M 次のような △ABCにおいて, 外接円の半径R を求めよ。 (1) a=3, A=120° (2) c=10, C=45° 3 2720 2R- R = 40 T 80 = 2 R₂ 102 102 459 = 2R 12 R R at fith E 1/10/