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Mathematics Senior High

(3)ってどういうことですか? このグラフの頂点は -2a/b,-4a/b^2-4ac ですよね? それで、グラフを見ると頂点のY座標が正だったので Cはプラスだと思いました。 なんで違うのか教えてください😭🙇‍♀️

2次関数の係数の符号とグラフ 基本例題 52 2次関数y=ax2+bx+c のグラフが右の図で与えら れているとき,次の値の符号を調べよ。 (2) 6 (1) a (3) c (4) 62-4ac (5) a-b+c CHART & THINKING グラフから情報を読み取る 式の値は直接求めることができない。 「上に凸か,下に凸か」, 「軸や頂点の位置」, 「y軸との交点の位置」 などに着目して 式の値の符号を調べよう。 解答 har²+brto ax2+bx+c=ax+ \2 = a (x + b )²_b²-4ac 2a 4a 62-4ac 4a 上に凸か, 下に凸か? (1) グラフは上に凸の放物線であるから UNDRICAS (2) 軸がx<0 の部分にあるから 敵の (1) より, a<0であるから (3) グラフがy軸の負の部分と交わるから y=a(-1)2+b(-1)+c=a-b+c a<0 ax²+bx+c ²5-ye よって, 放物線y=ax2+bx+c の軸は直線x=-- b = a(x² + x)+c a 2a' 頂点のy座標は る。 1+S-N == また, x=-1のとき b 2a 軸の 位置は? <0 b<0 c<0 b y軸との交点のy座標はcであ =q{(x+2 a) ² - ( 23 ) ²} + c 2a z²-4ac >0 4a UA 10 A p.91 基本事項 4 基本51 ya (4) 頂点のy座標が正であるから (1) より, a<0であるから -(6²-4ac) <0 すなわち b²-4ac>0 (5) a-b+cは,x=-1におけるyの値である。 グラフから,x=-1 のとき y>0 すなわち a-b+c>0 10 00000 6\2 ST389=a(x+2)²-a ( 20 )² + c 2a 頂点のy座標は? x=-1 における y 座標は ? x 軸との交点の 位置は? b 2a a√x+- za = a√x+· b AX 6 \2 2a ->0 b²-4ac 4a ACESTE ←放物線y=ax²+bx+c について, x軸と異なる2点で交 わる ⇔ b2-4ac>0 が成り立つ (p.139 以降 を参照)。 97 3 P B ニ

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English Junior High

なぜ、答えが 『エ』ではなく 『ウ』になるのか 教えてほしいです🙇‍♀️

次の英文を読んで、問1~問5に答えなさい。 *印のついている語句には,本文のあとに〔注〕があります。(10分) A 1901, the Nobel Prize has *honored men and women from all over the world for great work in science, writing, and peace. The Nobel Prize is an *award that was started in Sweden. The name Nobel Prize comes from a Swedish scientist, Alfred Nobel, who made more than 350 *inventions. In 1895, a year betore he died. he set up the award. Many people think the Nobel Prize is the greatest award a person can receive. Twenty two people from Japan have received the Nobel Prize. Recently, awards were given to three scientists from Japan in 2014 (for their work in science. These three scientists, Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura, made a bright blue *LED in the 1990s. All three colors are needed to make a white LED. White LEDs are bright, last for a long time, and don't use much *energy. Because of this, white LEDs are becoming more and more popular. They are B than fluorescent lights or *incandescent lights, but people can use them for a longer time. People can use LEDs for about 100,000 hours. That is 10 times as long as people can use fluorescent lights and 100 times as long as people can use incandescent lights. (2 Perhaps you are thinking that these scientists are cleverer than you. Their invention is really special, but they are people just like you. (3) People said that they could not do it. They had to make their own *equipment for their work. they tried more than a thousand times, they still were not able to make a blue LED. But they never gave up and finally they did it. Perhaps one day, if you work hard, you will get the Nobel Prize, too. Nobel Prize ノーベル賞 award LED I'I ・発光ダイオード 蛍光灯 機器 ……………. fluorescent equipment 〜をたたえる 発明品 honor invention energy I: incandescent 白熱灯 .…....

Solved Answers: 2
English Junior High

なぜ、答えが『ウ』 ではなく『イ』なのか 教えてほしいです🙇‍♀️

次の英文を読んで、問1~問5に答えなさい。 *印のついている語句には,本文のあとに〔注〕があります。(10分) A 1901, the Nobel Prize has *honored men and women from all over the world for great work in science, writing, and peace. The Nobel Prize is an *award that was started in Sweden. The name Nobel Prize comes from a Swedish scientist, Alfred Nobel, who made more than 350 *inventions. In 1895, a year betore he died. he set up the award. Many people think the Nobel Prize is the greatest award a person can receive. Twenty two people from Japan have received the Nobel Prize. Recently, awards were given to three scientists from Japan in 2014 (for their work in science. These three scientists, Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura, made a bright blue *LED in the 1990s. All three colors are needed to make a white LED. White LEDs are bright, last for a long time, and don't use much *energy. Because of this, white LEDs are becoming more and more popular. They are B than fluorescent lights or *incandescent lights, but people can use them for a longer time. People can use LEDs for about 100,000 hours. That is 10 times as long as people can use fluorescent lights and 100 times as long as people can use incandescent lights. (2 Perhaps you are thinking that these scientists are cleverer than you. Their invention is really special, but they are people just like you. (3) People said that they could not do it. They had to make their own *equipment for their work. they tried more than a thousand times, they still were not able to make a blue LED. But they never gave up and finally they did it. Perhaps one day, if you work hard, you will get the Nobel Prize, too. Nobel Prize ノーベル賞 award LED I'I ・発光ダイオード 蛍光灯 機器 ……………. fluorescent equipment 〜をたたえる 発明品 honor invention energy I: incandescent 白熱灯 .…....

Solved Answers: 1
Mathematics Senior High

高一数学の不等式の証明です。 ⑵で黄色い線を引いてあるところが何しているか分かりません。特に左辺はなんでなったのか全く分からないです。 解説をお願いします🤲🏻🙇‍♀️

! 重要 例題 35 不等式の証明の拡張 |a|<1,|6|<1, |c|<1 のとき, 次の不等式が成り立つことを証明せよ。 基本 27,29 (2) abc+2>a+b+c (1) ab+1>a+b CHART & THINKING 似た問題 1 結果を使う 2 方法をまねる (1) 大小比較は差を作る方針。 (2) 文字が多いため, 差を作る方針では煩雑になる。 そこで, (2) は, (1) の2文字(a,b)か ら3文字(a,b,c)に拡張された問題であることに注目すると、1の方針で証明できる。 うだ。 (1) の結果をどのように利用すればよいだろうか? |a|<1,|6|<1から|ab|<1であることに注目。 また, (1) を1回利用して不十分な ら, 2回利用することも考えよう。 解答 $84 (= x +.00 (1) (ab+1)-(a+b)=(6−1)a-(6-1)=(a-1)(6-1) |a|<1, |6|<1であるから a-1<0, 6-1<0 よって (a-1)(b-1)>0 すなわち (ab+1)-(a+b)>0 したがって ab+1>a+b (2) |a|<16|6| < 1 であるから |ab|<1 |ab|<1,|c|<1 であるから, (1) を利用して (ab)c+1>ab+c abc +2 > ab+c+1 (ab+1)+c>(a+b)+c abc+2>a+b+c よって (1) から ゆえに 別解 (abc+2)(a+b+c)=(bc-1)a+2-b-c |b|<1, |c|<1 であるから よって bc-1<0 |a|<1 であるから a <1 ゆえに よって 0=(3+v)sv+x²(x+y) 0=(sx+*(s+x+ |bc|<1 ( bc-1)a>(bc-1)・1 ( bc-1)a+2-6-c>bc-1+2-6-c ■RACTICE 35° |b|<1, |c|<1 であるから ゆえに (b-1)(c-1)>0 したがって abc+2>a+b+c =(b-1)(c-1) 6-1<0,c-1 <0 大小比較差を作る -1<a<1, -1<6<1 S+V) ← 結果を使う TU (1) の不等式でαを abに bをcにおき換える。 ab+1>a+b の両辺に cを加える。 大小比較差を作る |-1<bc<1 α< 1 の両辺に 負の数 bc-1 を掛ける。

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