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Mathematics Undergraduate

なぜ黄色の線のようなことになるのでしょうか? tan(90°-α)=1/tanαとなることも分かりません。 すみませんが丁寧に解説していただけると助かります。🙏

3. LABC めよ。 基本12 a+b+cを これを書き になる。 のみを 用する。 ら、 きで 重要 例題 162 図形への応用 (2) 0000 点Pは円x2+y²=4上の第1象限を動く点であり, 点Qは円x2+y2=16上の第 2象限を動く点である。ただし,原点0に対して,常に ∠POQ=90° であるとす る。また、点Pから x軸に垂線PHを下ろし,点Qからx軸に垂線 QK を下ろ す。更に ∠POH=0 とする。このとき, AQKH の面積 S は tan0のと き最大値をとる。 [類 早稲田大〕 重要 159 指針> AQKH の面積を求めるには,辺KH,QK の長さがわかればよい。そのためには,点P と点 Qの座標を式に表すことがポイント。 半径rの円x2+y2=2上の点A(x,y) は, x=rcosa, y=rsina (aは動径 OA の表 す角) とおけることと,∠POQ=90°より,∠QOH=∠POH+90° であることに着目。 解答 OP= 2,∠POH=0であるから, Pの座標は (2 cos 0, 2 sin() 0Q=4,∠QOH=0+90° であるから,Qの座標は (4cos (+90°), 4sin (0+90°)) すなわち (4sin 0, 4cos 0 ) ただし 0°<0<90° ゆえに -1/213KHQK-2/12 (2cos0+4sin0) 4cos0 =2(2cos20+4sin Acos0 ) S= ゆえに =2(1+cos20+2sin20)=2{√5 sin (20+α)+1} = 1 √5' 2 ただし,αは sinα= √5 0°<< 90°から (0°<) a<20+a<180°+a (<270°) よって,Sは20+α=90°のとき最大値2(√5+1) をとる。 1 20+α=90°のとき tan20=tan (90°-α)= tan a =2 cos α = 2 tan 0 1-tan²0 0° 090° より tan 0 0 であるから tan0= , よって COS Q sin a =2 tan 20+ tan 0-1=0 1+√5 2 三角関数の合成。 0°<α <90° を満たす角。 α は具体的な角として表す ことはできない。 K sing= 練習 ② 162 に対して、次の条件 (a), (b) を満たす2点B, C を考える。 yA 2 O 4 0H2x P COS Q= √5 <tan 0 についての2次方程 式とみて解く。 (a) B はy>0 の部分にあり,OB=2 かつ∠AOB=180° -0である。 (b) Cはy<0 の部分にあり,OC=1かつ∠BOC=120° である。 ただし △ABC は 0 を含むものとする。 (1) △OAB とAOACの面積が等しいとき, 0 の値を求めよ。 2 /5 0を原点とする座標平面上に点A(-3,0)をとり, 0°<<120°の範囲にある ののの 253 4章 12 三角関数の合成 27

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TOEIC・English Undergraduate

答えを教えてください! よかったら,根拠も教えてください

la vitbl Questions 4-7 refer to the following letter. January 10 Ms. Erin Murphy Customer Service Department Westcoast Airlines Major Miles Program 345 Brook Street Dallas, TX 75218 Dear Ms. Murphy, As per your request during our telephone conversation on January 8, I am sending you Los Angeles International Airport last December. Please note that my ticket was upgraded itinerary and ticket number for my recent roundtrip flight from JFK International Airport business class with a Major Miles Gold Class voucher and should therefore be eligible f full business class mileage credit. 62 Section Il over 15 years. I must confess that I find the new restrictions to your flight voucher pla I am a Gold member in the Major Miles program and have been a Westcoast customer 1 genuinely confusing. I fail to understand why the burden of proof for my mileage cred rests with me. Shouldn't this information be on your ticketing computer? This was my itinerary. MD My ticket number was #YB42565697. Departed JFK, December 22 at 10:20 for LAX Returned to JFK from LAX on December 29 at 16:40 My seat number was 14B. 7B My Major Miles number is # 04356721 (Gold Card). I sincerely hope that this issue will be resolved quickly as I am counting on my miles eame during this trip to upgrade my hotel room next May. Thank you very much for your attention in this matter. Sincerely Yours, Jarrod Watkins Jarrod Watkins 4. 5. 6. What does Ms. Murphy do? (A) She makes airline reservations. (B) She deals with unhappy customers. (C) She issues new tickets. (D) She upgrades people to business class. What is the purpose of this letter? (A) To upgrade his ticket to business class (B) To buy a flight upgrade coupon (C) To complain about his seat reservation (D) To receive more mileage credits How does Mr. Watkins feel about the new frequent flier program rules? (A) He would like them to be simpler. (B) He believes they are unfair. (C) He finds them to be convenient. (D) He hopes that they will benefit hold Card members more. Which of the following is NOT mentioned in the letter? (A) His ticket number (B) His frequent flier level (C) His credit card number (D) His flight information inq M:8 big en enthovenot cold w lar hud,mq 01X in jord is di Hal Unit 2: Letters, E-mails, & Text message chains 63

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TOEIC・English Undergraduate

自分の回答と照らし合わせて確認したいので、答えがなにになるかどなたか教えてください。 解説もあると助かります。

5 A Matter of Taste Reading Passage 042 At the age of just 22, Jamie Oliver became well known across the UK as "The Naked Chef." He called himself this not because he cooked wearing no clothes, but because he wanted to simplify food preparation so that everybody could follow his recipes. He wanted to "strip down" the idea of cooking. Since then he has had numerous TV shows, published 50 many books, and has become a household name in the UK. Today, one of the activities Jamie Oliver is best known for is his great effort to improve the school dinners that children eat every day. One day, he visited the kitchen of a typical London secondary school, and he was shocked to see how much processed junk food the kids were given to eat each day. Fat and sugar levels were extremely high, and nutritional values very 10 low. The "turkey twizzler" became the symbol of these unhealthy meals: processed meat containing 21.2% fat and only 34% actual turkey. Oliver ran the school kitchen for one year and tried to show that it was possible to serve healthy meals on a limited budget—and that kids actually enjoyed eating them. His mission was to radically change the eating habits of children in that school, and across the country. 150 200 15 20 25 CULTIES 250 His project (the "Feed Me Better" campaign) has had some influence on school dinners in the UK. After watching the documentary Jamie's School Dinners, 271,677 people signed a petition calling for healthier school meals. This led the Prime Minister to agree to spend 280 million pounds (about 37 billion yen) on school dinners, to ban some junk food from school menus, and to create a School Food Trust to provide support and advice for people preparing school meals. Research, by the way, shows that children who stop eating sugary, fatty food and instead eat Oliver's school dinners are better behaved in class, and they get higher test 300 scores, too. 350 Of course, the project has had some problems. At first, many students (and even parents) resisted the removal of the junk food they were so used to. In one famous instance, some parents were passing local takeaway food to their children through the school fence. Also, schools that followed the plan for a while were often found to gradually drift back into bad habits. After all, it is easier and cheaper to just give the kids junk food. However, Oliver's efforts represent a positive start, and with obesity becoming such a huge problem (see Unit 4), 400 it's a very necessary start.

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