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日本史 高校生

黒の並々引いたとこどうやって出すかわかりません

51 領垣 実数x, y, 3.x+y≧6, 2x-y≦4, x+2y≦7 を同時にみた すとき,次の問いに答えよ. (1) 3.x-yのとりうる値の最大値、最小値を求めよ. (2)x2+y^ のとりうる値の最大値、最小値を求めよ. 精講 領域D内を点(x, y) が動くとき, x+yのとりうる値はどのよう 考えればよいのでしょうか。 たとえば, (x,y)= (1,1) としたときの x+yは2ですが、 29 〈図II〉より,y=3x-k がB(3,2)を通るときは最小で、 C(1,3)を通るとき,kは最大 すなわち, B(3,2)を通るときは 最大値 7 をとり C(1,3) を通るときは最小値 0 をとる. (2) (0) とおくと,これは原点中 心, 半径の円を表し、この図形が <図1> の色 の部分と共有点をもちながら動くときのの とりうる値の範囲を考えればよい。 y\ <図III> 3 2 B (i) 最大値 0 円がBを通るとき, r2は最大で、最大値は 22 13 1 A 3 (i) 最小値 y=3x56 円が直線 CA, すなわち, 3x+y-6=0 と接するときを考える。 だから とおいて、この直線がDと共有点を このとき、接点は、直線CA13の交点で (11) もちながら動くときの切片kのとりうる値の範囲を考え ればよいのです. 2 D (1,1)) 最小値は(1)+(3)-13 32 18 この点は線分 CA 上にあるので、この点がの最小値を与え, y-32+6 「2」はどこに現れているかというと, x+y=2 だから、直線の切片 現れています。 (右図参照) (右図で, x+y=k はDと共有点をもっています) たとえば,右図では点 (1,1) だけではなく, x+y=k 0 上の太線部分の点をすべて代入したことになっているのです. 85 注2+y^ は, (0, 0) と(x,y) との距離の平方と考えることもできます. ポイント 不等式が表す領域内の点(x, y) に対して, x, yの関 解答 3x+y≥6 連立不等式 2-y≦4 の表す領域は ブラスだす。 <図1> 3 〈図I〉の色の部分 (境界も含む). x+2y≤7 2 数 f(x, y) の最大値、最小値は Ⅰ. f(x,y)=kとおき Ⅱ.kが図形的に何を意味するかを考えて Ⅲ. f(x,y)=k が領域と共有点をもつように動かし、 k の最大、最小を考える (1) とおくと くと,領域がかきやすくなります。 注 境界になる3つの直線の交点を先に求めてお 12 3 O 1 A 演習問題 51 <図Ⅱ> x,yが4つの不等式 x0,y≧0, 2x+3y≦12, 2x+y≦8

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英語 高校生

教えてほしいです

3 次の英文を読み, 空所に入れるのに最も適切なものを, それぞれ下の①~④のうちから一つずつ選びなさい。 Cigarette smoking has negative effects not only on the body of the person who smokes but also on the body of someone who regularly breathes in second-hand smoke. Some of the most obvious effects are high blood pressure, sleep disorders, heart failure, and lung cancer. Despite such harmful consequences, ( 10 ). It has been reported that smoking creates feelings of pleasure, reduces tension, and promotes close relationships. Many smokers admit that smoking is a bad habit. ( 11 ), they tend to think that the number of cigarettes that they smoke is below the danger level and thus are not worried about the risk. Some even feel that they do not breathe in the smoke and that a cure for cancer will be found before they become ill with the disease. We have to admit that smoking is a habit which is difficult to break ( 12 ) the nicotine found in tobacco goes into the blood and stimulates the brain, making smokers feel pleasant for several minutes. What is more, the smoker usually feels anxious and wants to have another cigarette. ( 13 ) the policies that now ban smoking in most public areas, the stress that people often experience at work and at home can force them to smoke. ( 10 ) ①some people decide to stop smoking millions of people continue to smoke ( 11 ) the price of cigarettes has risen ①smoking is more harmful than drinking Therefore 2 While ③ Of course 4 However (12) 1 because 2 as a result 3 but SO (13) ①Despite 2 Although (3) But 4 Yet

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英語 高校生

教えてほしいです

2 次の英文を読み, 空所に入れるのに最も適切なものを,それぞれ下の①~④のうちから一つずつ選びなさい。 (6) When growing tomatoes, we know we should pick them when they're bright red. With carrots, however, ( 6 ) because they grow underground. ①we should pick them when they turn orange (2) it's hard to know when they're ready (3) we should grow them more carefully than tomatoes (4) it's easy to know when they're bright red (7) Although it is quick, easy and convenient to be able to look up information on the internet, it can sometimes be difficult ( 7 ) because there is so much information. to find what you are looking for (2) to improve the convenience of the internet (3) to get more than what you need that people often experie (4) to have good computer literacy (8) Would you be happier if you were richer? Many people believe that they would be. But research conducted over many years suggests that ( 8 ). People in the United States, for example, are, on average, richer than New Zealanders, but they are not happier. poorer people tend to worry about their financial problems 2 pleasure in life usually comes from great wealth (3) the best way to be happy is learning how to save money greater wealth doesn't generally imply greater happiness (9) Many European rivers were once heavily polluted by manufacturing industries. As a result, wild animals dependent on clean water disappeared. However, as stricter environmental standards took effect, rivers such as the Thames of London have become much cleaner. Consequently, ( 9 ). water quality has continued to decline wild animals avoid drinking from the Thames (3) wild animals are making a comeback in many rivers (4) wild animals no longer depend on clean water

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