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数学 高校生

この問題が解説を見てもよく分かりません 解説よろしくおねがいします🙇

も内 173 の 演習 例題 194 対数方程式の解の個数 00000 aは定数とする。 xの方程式 {10g2(x2+√2)}^2-210gz(x2+√2)+α=0の実数 解の個数を求めよ。 指針 前ページの演習例題 193 同様, おき換えにより, 2次方程式の問題に直す。 変数のおき換え 範囲に注意 log2(x2+√2)=tとおくと,方程式は t2-2t+a=0 (*) 基本 183 2√2の値の範囲を求め,その範囲におけるtの方程式(*)の解の個 数を調べる。それには,p.239 重要例題 149 と同様, グラフを利用する。 なお、10g2(x2+√2)=t における x と tの対応に注意する。 SELECT 解答 log2(x2+√2)=t $0.0> (Sargola) (1) ① とおくと, 方程式は t²-2t+a=0 0218.0 1108. 2+√2≧√2であるから 215 21 >01.0 311 10 10gz (x2+√2) log√2 したがって t≧ (2) E 226 227 228 229 230 231 22 233 234 また,①を満たすxの個数は,次のようになる。 =1/2のときx=0の1個, のとき x2>0であるから 2個 t2-2t+α=0から Slant (1) x2+√2=25より, x2=2√2 であるから t=1/2のとき x=0 1/1/3のときx>0 よって x=±√2-√2 -t2+2t=a 1 よって、②の範囲における, 直線 y=aを上下に動か 3 y=a 放物線y=-t2 + 2t と直線 y= a 4 a! 1 1 i して、共有点の個数を調 べる。 の共有点の座標に注意して, 01 方程式の実数解の個数を調べると, α>1のとき0個; a=1, a< a< 2 のとき2個; -12 1 2 32 共有点なし。 <t> // である共有点1個。 4 a= =2のとき3個; -<a<1のとき4個 <a 1 3 t= 2 2 \t> である共有点2個。

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英語 高校生

16はなぜAではだめなのでしょうか。 そして17の下線部のlikeは「好む」という意味で取ってないと思ったのでAにしたのですがどういうふうに解釈すればいいですか、、😭

4 Jim: (Questions 16 to 22) Read the conversation and select the best option for each question. Clerk: Can I help you? Yeah thanks do you have this blue shirt in a bigger size? I can only see “smalls” and "mediums" on the shelves... Clerk: Let me see... Sorry, but "large" is sold out. We don't have many long-sleeved shirts left because it's the end of winter, and that particular style has been popular. But we have it in an "extra-large," would you like to try it on? Jim: That sounds like it might be too big... Clerk: To be honest, these are slim-fit shirts, so an "extra-large" is more like a "large" in other styles. Jim: Oh really? OK, let me try it on... You're right, the fit around my body is perfect! But the sleeves are so long they cover my hands! Can you recommend anything else? Clerk: Hmmm... Do you mind if it's a different style? Jim: ( 16 ) I want a blue shirt, but apart from that I don't care much. Clerk: In that case, what about this short-sleeved blue shirt? It's "large," and it's from our Spring Collection. Jim: (17) Well, I know I said I didn't care much, but I'm not a fan of collars with buttons. I feel like I should be wearing a tie with those ones! Clerk: Ah, I see. Well, how do you feel about a patterned shirt? We have some nice blue shirts with stripes, dots, or flower designs. Jim: (18) Clerk: Sure. Here is a light blue one with thin stripes, and over there we have a dark blue one which comes in thin or thick stripes. 1:1-4h thick strines but that one only comes in dark blue, right? ined light

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英語 高校生

至急です。試験範囲なので教えてください🙏🙏

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